Updated on 2022/05/26

写真a

 
YAMANOCHI, Korehito
 
Affiliation
Faculty of Human Sciences
Job title
Professor Emeritus

Degree

  • Juntendo University School of Medicine   Ph.D.

Research Experience

  • 1992
    -
    Now

    prfofessor

  • 1987
    -
    Now

    Waseda University   School of Human Sciences

  • 1987
    -
    1992

    Faculty of Human Sciences, Waseda University

  • 1972
    -
    1987

    Juntendo University   Faculty of Medicine

  • 1972
    -
    1987

    Dept. of Anatomy, Juntendo University School of Medicine Research Associate

  • 1971
    -
    1972

    国立ガンセンター研究所薬効試験部 研修生

  • 1971
    -
    1972

    Pharmacology Division, National Cancer Center Research Inst.

  •  
     
     

    associate professor

▼display all

 

Research Areas

  • Morphology and anatomical structure

Research Interests

  • 神経内分泌学

  • Neuroendocrinology

Books and Other Publications

  • 母性をめぐる生物学―ねずみから学ぶ(齋藤徹編)

    アドスリー  2012

  • 「環境」人間科学(根ヶ山光一、中島義明編)

    朝倉書店  2008

  • 性差の人間科学

    コロナ社  2008 ISBN: 9784339077896

  • ホルモンの人間科学

    コロナ社  2006

  • 脳の性分化

    裳華房  2006 ISBN: 4785359137

  • 専門医をめざす人の精神医学第二版

    医学書院  2004

  • 女と男の人間科学

    コロナ社  2004 ISBN: 4339078387

  • 脳の人間科学

    コロナ社  2003 ISBN: 9784339077735

  • 母性と父性の人間科学(根ヶ山光一編)

    コロナ社  2001

  • 性を司る脳とホルモン

    コロナ社  2001 ISBN: 433907831X

  • 脳が子どもを産む

    平凡社  1999 ISBN: 4582841945

  • 性機能障害

    南山堂  1998

  • Advances in Comparative Endocrinology 2

    Monduzzi  1997

  • Neural Control of Reproduction-Physiology and Behavior

    Jap.Sci.Soc.Press/Elsevier  1997

  • Advances in Comparative Endocrinology 2

    Monduzzi  1997

  • Neural Control of Reproduction-Physiology and Behavior

    Jap.Sci.Soc.Press/Elsevier  1997

  • Sexuality and Human Bonding

    Elsevier/Amsterdam  1996

  • Sexuality and Human Bonding

    Elsevier/Amsterdam  1996

  • 新医科学大系10-脳と行動

    中山書店  1994

  • Toxicity of Hormones in Perinatal Life

    CRC press, Boca Raton  1988

  • Toxicity of Hormones in Perinatal Life

    CRC press, Boca Raton  1988

  • 神経内分泌 3巻

    中外医学社  1986

  • Emotions-Neuronal and Chemical Control

    Japan Sci. Soc. Press, Tokyo/Karger, New York,  1986

  • Emotions-Neuronal and Chemical Control

    Japan Sci. Soc. Press, Tokyo/Karger, New York,  1986

  • 行動とホルモン-ホルモンの生物科学

    会出版センター  1983

  • Neuroendocrine control mechanisms of female sexual behavior (共著)

    Endocrinology-ICS 598、Elsevier。  1983

  • Neuroendocrine control mechanisms of female sexual behavior (共著)

    Endocrinology-ICS 598、Elsevier。  1983

  • ホルモン生物学-実験生物学講座12

    丸善  1982

  • Integrative Control Functions of the Brain, Vol. 2

    Kodansha/Elsevier  1979

  • Integrative Control Functions of the Brain, Vol. 2

    Kodansha/Elsevier  1979

  • ntegrative Control Functions of the Brain, Vol. 1

    Kodansha/Elsevier  1978

  • ntegrative Control Functions of the Brain, Vol. 1

    Kodansha/Elsevier  1978

▼display all

Misc

  • Synthesis and bioassay of a boron-dipyrromethene derivative of estradiol for fluorescence imaging in vivo

    Mayumi Okamoto, Shun Kobayashi, Hiroshi Ikeuchi, Shunji Yamada, Korehito Yamanouchi, Kazumichi Nagasawa, Shun Maekawa, Takashi Kato, Isao Shimizu

    STEROIDS   77 ( 8-9 ) 845 - 849  2012.07

     View Summary

    C7 alpha-substituted estradiols bind to estrogen receptors in cell nuclei, yet these derivatives remain little used in bioimaging. Here, we describe a fluorescent derivative of estradiol (E2) with a boron-dipyrromethene (BODIPY) moiety attached to C7 alpha, synthesized by olefin metathesis reaction of 7 alpha-allylestradiol and 9-decenyl-BODIPY. In ovariectomized rats and non-ovariectomized mice, E2-BODIPY promoted the growth of uterine tissue similar to the effect of estradiol. Twenty-four hours after subcutaneous injection of E2-BODIPY in non-ovariectomized mice, we observed fluorescence of E2-BODIPY in the nuclei of uterine epithelial cells. Our findings suggest that fluorescence microscopy can localize this derivative in E2-responsive cells during normal development and tumorigenesis in vivo. (c) 2012 Elsevier Inc. All rights reserved.

    DOI

  • Synthesis and bioassay of a boron-dipyrromethene derivative of estradiol for fluorescence imaging in vivo

    Mayumi Okamoto, Shun Kobayashi, Hiroshi Ikeuchi, Shunji Yamada, Korehito Yamanouchi, Kazumichi Nagasawa, Shun Maekawa, Takashi Kato, Isao Shimizu

    STEROIDS   77 ( 8-9 ) 845 - 849  2012.07

     View Summary

    C7 alpha-substituted estradiols bind to estrogen receptors in cell nuclei, yet these derivatives remain little used in bioimaging. Here, we describe a fluorescent derivative of estradiol (E2) with a boron-dipyrromethene (BODIPY) moiety attached to C7 alpha, synthesized by olefin metathesis reaction of 7 alpha-allylestradiol and 9-decenyl-BODIPY. In ovariectomized rats and non-ovariectomized mice, E2-BODIPY promoted the growth of uterine tissue similar to the effect of estradiol. Twenty-four hours after subcutaneous injection of E2-BODIPY in non-ovariectomized mice, we observed fluorescence of E2-BODIPY in the nuclei of uterine epithelial cells. Our findings suggest that fluorescence microscopy can localize this derivative in E2-responsive cells during normal development and tumorigenesis in vivo. (c) 2012 Elsevier Inc. All rights reserved.

    DOI

  • Defeminization of Brain Functions by a Single Injection of Estrogen Receptor alpha or beta Agonist in Neonatal Female Rats

    Moeko Kanaya, Korehito Yamanouchi

    NEUROENDOCRINOLOGY   95 ( 4 ) 297 - 304  2012

     View Summary

    Sexual differentiation of brain function is regulated by estrogen in the perinatal period of rodents. However, the role of the estrogen receptor subtypes ER alpha and ER beta is still in question. Accordingly, the effects of neonatal treatment with the ERa agonist propyl pyrazole trio! (PPT) or the ER beta agonist diarylpropionitrile (DPN) on female reproductive functions were investigated in rats. Female rats were injected subcutaneously with 100-500 mu g/10 g body weight (b.w.) PPT or DPN, 100 mu g/10 g b.w. estradiol (E-2), or saline at day 5 (birth day = day 1), and then vaginal opening and vaginal smears were examined. On day 60, their ovaries were removed and lordosis behavior was observed after subcutaneous implantation of a silicon tube containing E-2. As a result, in most PPT and all E-2 rats, vaginal opening was advanced and an irregular estrous cycle was observed. In contrast, in most rats of the DPN groups, vaginal opening was comparable to that of the control and there was a regular estrous cycle. Lordosis tests revealed that the mean lordosis quotients (LQs) in the 250- and 500-mu g PPT groups was lower than in the saline group, but higher than in the E-2 group. Mean LQs in all DPN groups were comparable to those in the saline group. These results suggest that ER alpha plays a major role in masculinization of the system regulating the estrous cycle in the rat brain. In behavioral defeminization of the lordosis-regulation system, ERa was also found to be the main target of estrogen. Copyright (C) 2012S. Karger AG, Basel

    DOI PubMed

  • Defeminization of Brain Functions by a Single Injection of Estrogen Receptor alpha or beta Agonist in Neonatal Female Rats

    Moeko Kanaya, Korehito Yamanouchi

    NEUROENDOCRINOLOGY   95 ( 4 ) 297 - 304  2012

     View Summary

    Sexual differentiation of brain function is regulated by estrogen in the perinatal period of rodents. However, the role of the estrogen receptor subtypes ER alpha and ER beta is still in question. Accordingly, the effects of neonatal treatment with the ERa agonist propyl pyrazole trio! (PPT) or the ER beta agonist diarylpropionitrile (DPN) on female reproductive functions were investigated in rats. Female rats were injected subcutaneously with 100-500 mu g/10 g body weight (b.w.) PPT or DPN, 100 mu g/10 g b.w. estradiol (E-2), or saline at day 5 (birth day = day 1), and then vaginal opening and vaginal smears were examined. On day 60, their ovaries were removed and lordosis behavior was observed after subcutaneous implantation of a silicon tube containing E-2. As a result, in most PPT and all E-2 rats, vaginal opening was advanced and an irregular estrous cycle was observed. In contrast, in most rats of the DPN groups, vaginal opening was comparable to that of the control and there was a regular estrous cycle. Lordosis tests revealed that the mean lordosis quotients (LQs) in the 250- and 500-mu g PPT groups was lower than in the saline group, but higher than in the E-2 group. Mean LQs in all DPN groups were comparable to those in the saline group. These results suggest that ER alpha plays a major role in masculinization of the system regulating the estrous cycle in the rat brain. In behavioral defeminization of the lordosis-regulation system, ERa was also found to be the main target of estrogen. Copyright (C) 2012S. Karger AG, Basel

    DOI PubMed

  • Acceleration of irregular estrous cycle in forced running by midbrain raphe lesions in female rats

    Hideo Shimizu, Korehito Yamanouchi

    Neuroscience Letters   495 ( 3 ) 192 - 195  2011.05

     View Summary

    It is known that over-exercise or forced running interrupts the regular ovulatory (estrous) cycle in female mammals, including women. The serotonin content of the brain changes under stress conditions. In this experiment, radiofrequency lesions were made in the dorsal (DRL) or median (MRL) raphe nuclei of the midbrain, in which serotonergic neurons are abundant, and changes in the estrous cycle with forced running using an electric-motor running wheel were examined in female rats. Through the tests, the estrous cycle was checked by taking vaginal smears. Female rats with a regular 4-day estrous cycle were forced to run in the wheel for 30. min daily over 15 days. As a result, 27.3% of the control and 30.0% of the sham-operated rats showed an irregular estrous cycle. In contrast, 100% of the DRL and 87.5% of the MRL rats showed an irregular cycle (P&lt
    0.05 vs. control and sham). Statistical analysis revealed that the median onset day of an irregular cycle was in excess of 15 days in both the control and sham groups. In the DRL and MRL groups, the median onset days of the irregular cycle were day 5 and 3, respectively, being shorter than those in control and sham groups (P&lt
    0.01). These results indicate that the dorsal and median raphe nuclei play an important role in preventing the effect of stress conditions in the ovulatory system in female rats. © 2011 Elsevier Ireland Ltd.

    DOI PubMed

  • Acceleration of irregular estrous cycle in forced running by midbrain raphe lesions in female rats

    Hideo Shimizu, Korehito Yamanouchi

    NEUROSCIENCE LETTERS   495 ( 3 ) 192 - 195  2011.05

     View Summary

    It is known that over-exercise or forced running interrupts the regular ovulatory (estrous) cycle in female mammals, including women. The serotonin content of the brain changes under stress conditions. In this experiment, radiofrequency lesions were made in the dorsal (DRL) or median (MRL) raphe nuclei of the midbrain, in which serotonergic neurons are abundant, and changes in the estrous cycle with forced running using an electric-motor running wheel were examined in female rats. Through the tests, the estrous cycle was checked by taking vaginal smears. Female rats with a regular 4-day estrous cycle were forced to run in the wheel for 30 min daily over 15 days. As a result, 27.3% of the control and 30.0% of the sham-operated rats showed an irregular estrous cycle. In contrast, 100% of the DRL and 87.5% of the MRL rats showed an irregular cycle (P < 0.05 vs. control and sham). Statistical analysis revealed that the median onset day of an irregular cycle was in excess of 15 days in both the control and sham groups. In the DRL and MRL groups, the median onset days of the irregular cycle were day 5 and 3, respectively, being shorter than those in control and sham groups (P < 0.01). These results indicate that the dorsal and median raphe nuclei play an important role in preventing the effect of stress conditions in the ovulatory system in female rats. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

    DOI PubMed

  • Sex and regional differences in decrease of serotonin-immunoreactive cells by parachlorophenylalanine in rat raphe nuclei

    Hiroyuki Ito, Korehito Yamanouchi

    NEUROSCIENCE RESEARCH   67 ( 1 ) 33 - 39  2010.05

     View Summary

    To determine sex and regional differences in the properties of serotonin (5-HT) neurons of the raphe nuclei, the responsiveness to parachlorophenylalanine (PCPA) of 5-HT neurons in the dorsal and median raphe nuclei (DR and MR) and the nucleus raphe magnus (RMg) was analyzed by counting 5-HT-immunoreactive (5-HT-ir) cells. Gonadectomized male (OCX) and female (OVX) rats were treated with 100 mg/kg b.wt PCPA or saline daily for 4 days. The brains were removed and fixed one day after the last injection. Frozen sections were stained with serotonin antibody and the numbers of 5-HT-ir cells in the raphe nuclei were counted. As a result, in female rats, the densities of 5-HT-ir cells in these 3 raphe nuclei were almost the same when compared the PCPA-treated and saline-treated groups. On the other hand, in male rats, the densities of 5-HT-ir cells in the DR and MR of PCPA-treated rats were lower than in saline-treated rats. In the male RMg, no difference was seen. These results suggest that responsiveness of 5-HT neurons to PCPA in the DR and MR, but not in the RMg, were sexually dimorphic. (C) 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

    DOI PubMed CiNii

  • Sex and regional differences in decrease of serotonin-immunoreactive cells by parachlorophenylalanine in rat raphe nuclei

    Hiroyuki Ito, Korehito Yamanouchi

    Neuroscience Research   67 ( 1 ) 33 - 39  2010.05

     View Summary

    To determine sex and regional differences in the properties of serotonin (5-HT) neurons of the raphe nuclei, the responsiveness to parachlorophenylalanine (PCPA) of 5-HT neurons in the dorsal and median raphe nuclei (DR and MR) and the nucleus raphe magnus (RMg) was analyzed by counting 5-HT-immunoreactive (5-HT-ir) cells. Gonadectomized male (OCX) and female (OVX) rats were treated with 100. mg/kg b.wt PCPA or saline daily for 4 days. The brains were removed and fixed one day after the last injection. Frozen sections were stained with serotonin antibody and the numbers of 5-HT-ir cells in the raphe nuclei were counted. As a result, in female rats, the densities of 5-HT-ir cells in these 3 raphe nuclei were almost the same when compared the PCPA-treated and saline-treated groups. On the other hand, in male rats, the densities of 5-HT-ir cells in the DR and MR of PCPA-treated rats were lower than in saline-treated rats. In the male RMg, no difference was seen. These results suggest that responsiveness of 5-HT neurons to PCPA in the DR and MR, but not in the RMg, were sexually dimorphic. © 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society.

    DOI PubMed CiNii

  • Sex and regional differences in decrease of estrogen receptor alpha-immunoreactive cells by estrogen in rat hypothalamus and midbrain

    Shunji Yamada, Daisuke Noguchi, Hiroyuki Ito, Korehito Yamanouchi

    NEUROSCIENCE LETTERS   463 ( 2 ) 135 - 139  2009.10

     View Summary

    Sensitivity of neurons to estrogen in down-regulation of estrogen receptor alpha (ER alpha) can be thought to make a sex difference in regulatory system of reproductive activities. In this study, to investigate the sex difference of expression of ER alpha in the hypothalamus and midbrain, the number of ER alpha immunoreactive (-ir) cells was counted in orchidectomized (OCX) and ovariectomized (OVX) rats with or without treatment with estrogen. A week after the gonadectomy, 5 rats in each female and male were injected with 1 mg estradiol benzoate (EB). The remaining 5 rats in both sexes did not receive EB. The brain was fixed 24 h after EB-injection and 50 mu m-serial frozen sections were made. After immunohistochemical staining for ER alpha, the number of ER alpha-ir cells was counted in a 0.2-mm(2) frame in the anteroventral periventricular nucleus (AVPvN), the ventrolateral part of the ventromedial hypothalamic nucleus (vIVMN), the arcuate nucleus (ARCN), and the lateral mesencephalic central gray (IMCG) in 2 or 3 sections. The total number of ER alpha-ir cells was changed to a density value (number per 1 mm(3)). As the results, in EB-treated rats, the density of ER alpha-ir cells in all regions, except the male AVPvN and male IMCG, were lower than those in untreated rats of both sexes. In the vIVMN, the density of ER alpha-ir cells in OVX rats was higher than in OCX rats. These results suggest that there are sex and regional differences in the mechanisms of down-regulation of ER alpha by estrogen in the rat brain. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

    DOI

  • Sex and regional differences in decrease of estrogen receptor alpha-immunoreactive cells by estrogen in rat hypothalamus and midbrain

    Shunji Yamada, Daisuke Noguchi, Hiroyuki Ito, Korehito Yamanouchi

    NEUROSCIENCE LETTERS   463 ( 2 ) 135 - 139  2009.10

     View Summary

    Sensitivity of neurons to estrogen in down-regulation of estrogen receptor alpha (ER alpha) can be thought to make a sex difference in regulatory system of reproductive activities. In this study, to investigate the sex difference of expression of ER alpha in the hypothalamus and midbrain, the number of ER alpha immunoreactive (-ir) cells was counted in orchidectomized (OCX) and ovariectomized (OVX) rats with or without treatment with estrogen. A week after the gonadectomy, 5 rats in each female and male were injected with 1 mg estradiol benzoate (EB). The remaining 5 rats in both sexes did not receive EB. The brain was fixed 24 h after EB-injection and 50 mu m-serial frozen sections were made. After immunohistochemical staining for ER alpha, the number of ER alpha-ir cells was counted in a 0.2-mm(2) frame in the anteroventral periventricular nucleus (AVPvN), the ventrolateral part of the ventromedial hypothalamic nucleus (vIVMN), the arcuate nucleus (ARCN), and the lateral mesencephalic central gray (IMCG) in 2 or 3 sections. The total number of ER alpha-ir cells was changed to a density value (number per 1 mm(3)). As the results, in EB-treated rats, the density of ER alpha-ir cells in all regions, except the male AVPvN and male IMCG, were lower than those in untreated rats of both sexes. In the vIVMN, the density of ER alpha-ir cells in OVX rats was higher than in OCX rats. These results suggest that there are sex and regional differences in the mechanisms of down-regulation of ER alpha by estrogen in the rat brain. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

    DOI

  • ロードーシス制御におけるGABAaとGABAb受容体

    山内兄人, 掛山正心

    生体の科学   60 ( 5 ) 382 - 383  2009

    DOI

  • ロードーシス神経制御機構の性差

    山内兄人, 塚原伸治

    クリニカルニューロサイエンス   27 ( 10 ) 1120 - 1123  2009

  • Additive inhibition of lordosis by simultaneous treatments with GABA(A) and GABA(B) receptor agonists, muscimol and baclofen, in female rats

    Shizuko Wada, Shunji Yamada, Korehito Yamanouchi

    PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR   90 ( 4 ) 590 - 593  2008.10

     View Summary

    In order to investigate the relationship between GABA(A) and GABA(B) receptors in the induction of lordosis behavior, agonists of these receptor subtypes were injected simultaneously to estrogen-treated ovariectomized rats and lordosis behavior was observed before and after the injections. The GABAA receptor agonist, muscimol (MUS). at a dose in the range from 1.0 to 1.4 mg/kg body weight (bw) or the GAEA(B) receptor agonist, baclofen (BAC) at a dose in the range from I to 10 mg/kg bw, was injected intraperitoneally. The lordosis quotient (LQ) decreased after treatments with MUS or BAC and a dose-dependent decrease of LQ was observed in MUS or BAC-treated rats. When 1.2 mg/kg bw MUS and 5 mg/kg bw BAC were injected simultaneously, the mean LQ decreased strongly and was significantly lower than the values obtained after single injections of the agonists at these doses (P < 0.05). In addition, to ascertain the time-course of changes, a behavioral test was carried out 7 times from 15 to 180 min after the injection of agonists. The low LQ in the rats injected with both MUS and BAC continued longer than in rats given single injections. These results indicate that both GABAA and GABAB receptors are involved in lordosis-inhibiting mechanisms by the GABA neuron and operate independently. (c) 2008 Elsevier Inc. All rights reserved.

    DOI

  • Additive inhibition of lordosis by simultaneous treatments with GABA(A) and GABA(B) receptor agonists, muscimol and baclofen, in female rats

    Shizuko Wada, Shunji Yamada, Korehito Yamanouchi

    PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR   90 ( 4 ) 590 - 593  2008.10

     View Summary

    In order to investigate the relationship between GABA(A) and GABA(B) receptors in the induction of lordosis behavior, agonists of these receptor subtypes were injected simultaneously to estrogen-treated ovariectomized rats and lordosis behavior was observed before and after the injections. The GABAA receptor agonist, muscimol (MUS). at a dose in the range from 1.0 to 1.4 mg/kg body weight (bw) or the GAEA(B) receptor agonist, baclofen (BAC) at a dose in the range from I to 10 mg/kg bw, was injected intraperitoneally. The lordosis quotient (LQ) decreased after treatments with MUS or BAC and a dose-dependent decrease of LQ was observed in MUS or BAC-treated rats. When 1.2 mg/kg bw MUS and 5 mg/kg bw BAC were injected simultaneously, the mean LQ decreased strongly and was significantly lower than the values obtained after single injections of the agonists at these doses (P < 0.05). In addition, to ascertain the time-course of changes, a behavioral test was carried out 7 times from 15 to 180 min after the injection of agonists. The low LQ in the rats injected with both MUS and BAC continued longer than in rats given single injections. These results indicate that both GABAA and GABAB receptors are involved in lordosis-inhibiting mechanisms by the GABA neuron and operate independently. (c) 2008 Elsevier Inc. All rights reserved.

    DOI

  • Ipsilateral and contralateral serotonergic projections from dorsal and median raphe nuclei to the forebrain in rats: Immunofluorescence quantitative analysis

    Kouta Kanno, Satoshi Shima, Yuki Ishida, Korehito Yamanouchi

    NEUROSCIENCE RESEARCH   61 ( 2 ) 207 - 218  2008.06

     View Summary

    The objective of this study was to clarify the 5-HT projections from the right and left sides of the dorsal (DRD), ventral (DRV) and lateral (DRL) subdivisions of the middle level of the dorsal (DR) raphe nucleus and median (MR) raphe nucleus to the lateral septum (LS), preoptic area (POA) or ventromedial hypothalamus (VMH), which are important neural substrates for neuroendocrine regulation of reproduction. A retrograde neural tracer, Fluoro-Gold (FG), was infused into the right side of these regions in ovariectomized rats and the numbers of FG and/or 5-HT immunopositive cells in the right and left sides of the raphe nuclei were counted. It was found that the POA and VMH received more 5-HT projections than the LS from the DR and MR. In the subdivisions of the DR, 70% of all 5-HT projections from the DR to these 3 areas originated from the DRL. Furthermore, ipsilateral projections from the DR to the POA and VMH but not to the LS were dominant, compared to the contralateral projections. A right-left difference was not seen among the MR 5-HT projections. Thus, laterality of the projections is thought to be strong in the 5-HT clusters located far from the midline of the midbrain raphe nuclei. (c) 2008 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

    DOI PubMed

  • Ipsilateral and contralateral serotonergic projections from dorsal and median raphe nuclei to the forebrain in rats: Immunofluorescence quantitative analysis

    Kouta Kanno, Satoshi Shima, Yuki Ishida, Korehito Yamanouchi

    NEUROSCIENCE RESEARCH   61 ( 2 ) 207 - 218  2008.06

     View Summary

    The objective of this study was to clarify the 5-HT projections from the right and left sides of the dorsal (DRD), ventral (DRV) and lateral (DRL) subdivisions of the middle level of the dorsal (DR) raphe nucleus and median (MR) raphe nucleus to the lateral septum (LS), preoptic area (POA) or ventromedial hypothalamus (VMH), which are important neural substrates for neuroendocrine regulation of reproduction. A retrograde neural tracer, Fluoro-Gold (FG), was infused into the right side of these regions in ovariectomized rats and the numbers of FG and/or 5-HT immunopositive cells in the right and left sides of the raphe nuclei were counted. It was found that the POA and VMH received more 5-HT projections than the LS from the DR and MR. In the subdivisions of the DR, 70% of all 5-HT projections from the DR to these 3 areas originated from the DRL. Furthermore, ipsilateral projections from the DR to the POA and VMH but not to the LS were dominant, compared to the contralateral projections. A right-left difference was not seen among the MR 5-HT projections. Thus, laterality of the projections is thought to be strong in the 5-HT clusters located far from the midline of the midbrain raphe nuclei. (c) 2008 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

    DOI PubMed

  • Effects of estrogen, androgen, and phytoestrogen on retrieving and licking behaviors in nulliparous and male rats

    Mariko Sakai, Korehito Yamanouchi

    ZOOLOGICAL SCIENCE   24 ( 9 ) 894 - 898  2007.09

     View Summary

    In order to examine the effects of estrogen, androgen, and phytoestrogen on maternal behavior induced by exposure to fresh pups in ovariectomized nulliparous rats, 1 mg estradiol benzoate (EB), 1 mg testosterone propionate (TP), 1 mg coumestrol (CM), or oil (female control) was injected subcutaneously daily for 10 days. To elucidate the sex difference, 1 mg EB or oil (male control) was injected in orchidectomized rats by the same method as that used in nulliparous rats. Exposure to fresh pups was started 6 days after the first injection. Behavioral tests were carried out daily for 5 days from the first exposure to the last on the 10th day. In the behavioral test, the onset of retrieving and licking behaviors was recorded. In female control rats, the median onset day of retrieving behavior was day 5. Onset in the EB female group was day 1.5, which was shorter than that in the female control (P<0.05). TP female and CM female rats started to show retrieving at day 5 and day 4.5, respectively, comparable to the female controls. In males, the median day of retrieving onset in the control and EB groups was over day 5 and day 4.5, respectively. No statistical difference was seen between the female and male controls. In contrast, there was a difference between the EB-treated female and EB male groups. Licking activity was less frequent than seen in the retrieving behavior among all groups, but there was no statistical difference among the groups. These results suggest that estrogen facilitates retrieving behavior in female, but not in male rats. TP and CM have no effect on retrieving behavior in female rats.

    DOI PubMed CiNii

  • Effects of estrogen, androgen, and phytoestrogen on retrieving and licking behaviors in nulliparous and male rats

    Mariko Sakai, Korehito Yamanouchi

    ZOOLOGICAL SCIENCE   24 ( 9 ) 894 - 898  2007.09

     View Summary

    In order to examine the effects of estrogen, androgen, and phytoestrogen on maternal behavior induced by exposure to fresh pups in ovariectomized nulliparous rats, 1 mg estradiol benzoate (EB), 1 mg testosterone propionate (TP), 1 mg coumestrol (CM), or oil (female control) was injected subcutaneously daily for 10 days. To elucidate the sex difference, 1 mg EB or oil (male control) was injected in orchidectomized rats by the same method as that used in nulliparous rats. Exposure to fresh pups was started 6 days after the first injection. Behavioral tests were carried out daily for 5 days from the first exposure to the last on the 10th day. In the behavioral test, the onset of retrieving and licking behaviors was recorded. In female control rats, the median onset day of retrieving behavior was day 5. Onset in the EB female group was day 1.5, which was shorter than that in the female control (P<0.05). TP female and CM female rats started to show retrieving at day 5 and day 4.5, respectively, comparable to the female controls. In males, the median day of retrieving onset in the control and EB groups was over day 5 and day 4.5, respectively. No statistical difference was seen between the female and male controls. In contrast, there was a difference between the EB-treated female and EB male groups. Licking activity was less frequent than seen in the retrieving behavior among all groups, but there was no statistical difference among the groups. These results suggest that estrogen facilitates retrieving behavior in female, but not in male rats. TP and CM have no effect on retrieving behavior in female rats.

    DOI PubMed CiNii

  • Postnatal development of septal projections to the midbrain central gray in female rats: Tract-tracing analysis with DiI

    Tom Kouki, Korehito Yamanouchi

    NEUROSCIENCE LETTERS   411 ( 1 ) 37 - 41  2007.01

     View Summary

    The neural, projection of the lateral septum (LS) to the rostral mesencephalic central gray (MCG) is sexually dimorphic and plays an important role in inhibiting female reproductive behavior. In this experiment, development of the LS-MCG connection from birth to 15 days after birth was examined in female rats by a tract-tracing method with DiI. On the birth day (D1 rat), and 5, 10 or 15 days after birth (D5, D10 or D15 rat, respectively) or 8 weeks after birth (adult), the brain was fixed by perfusion of a mixture of 4% PFA and 0.1% glutaraldehyde. DiI was pasted on the coronally cut-surface of the LS and the sample was incubated in PEA at 40 degrees C for up to 4 months. After incubation, 200-mu m frozen parasagital sections were prepared and observed by fluorescence microscopy. As a result, numerous DiI labeled fibers were found in the preoptic area, the anterior and posterior hypothalamus, and the MCG in adult rats. In D1 rats, several labeled axons extended caudal to the anterior hypothalamic area. In D5 rats, a few labeled fibers reached the MCG. Some labeled fibers were observed in the rostral MCG of D10 rats. In D15 rats, a considerable number of labeled fibers were seen to reach the rostral MCG and relative density of the fibers was comparable to that of adult. These results suggest that the neural pathway from the LS to the rostral MCG develops acutely during the period from 5-10 days up to more than 15 days after birth. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

    DOI

  • Postnatal development of septal projections to the midbrain central gray in female rats: Tract-tracing analysis with DiI

    Tom Kouki, Korehito Yamanouchi

    NEUROSCIENCE LETTERS   411 ( 1 ) 37 - 41  2007.01

     View Summary

    The neural, projection of the lateral septum (LS) to the rostral mesencephalic central gray (MCG) is sexually dimorphic and plays an important role in inhibiting female reproductive behavior. In this experiment, development of the LS-MCG connection from birth to 15 days after birth was examined in female rats by a tract-tracing method with DiI. On the birth day (D1 rat), and 5, 10 or 15 days after birth (D5, D10 or D15 rat, respectively) or 8 weeks after birth (adult), the brain was fixed by perfusion of a mixture of 4% PFA and 0.1% glutaraldehyde. DiI was pasted on the coronally cut-surface of the LS and the sample was incubated in PEA at 40 degrees C for up to 4 months. After incubation, 200-mu m frozen parasagital sections were prepared and observed by fluorescence microscopy. As a result, numerous DiI labeled fibers were found in the preoptic area, the anterior and posterior hypothalamus, and the MCG in adult rats. In D1 rats, several labeled axons extended caudal to the anterior hypothalamic area. In D5 rats, a few labeled fibers reached the MCG. Some labeled fibers were observed in the rostral MCG of D10 rats. In D15 rats, a considerable number of labeled fibers were seen to reach the rostral MCG and relative density of the fibers was comparable to that of adult. These results suggest that the neural pathway from the LS to the rostral MCG develops acutely during the period from 5-10 days up to more than 15 days after birth. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

    DOI

  • Effects of 5-HT1A-receptor agonist, 8-OH-DPAT, and GABA(B)-receptor agonist, baclofen, on lordosis in female rats with lesions in either the dorsal raphe nucleus or septum

    M Kishitake, K Yamanouchi

    JOURNAL OF PHARMACOLOGICAL SCIENCES   98 ( 4 ) 419 - 424  2005.08

     View Summary

    The inhibitory effects of 8-OH-DPAT, a 5-HT1A-receptor agonist, and baclofen, a GABA(B)-receptor agonist, on lordosis were examined in estrogen and progesterone-treated ovariectomized rats with lesions in either the dorsal raphe nucleus (DRN) or septum and in rats with either sham lesions or no lesions. The first behavior test series was carried out 6 days after implantation of the rats with silicon tubes containing estradiol. Four hours after injection with 0.5 mg progesterone, behavioral tests were performed before and 30 min after an injection with 1 mg/kg body weight 8-OH-DPAT. As a result, the mean lordosis quotient (LQ)s were changed from 100 to less than 20 before and after the injection in all groups. These results suggest that 8-OH-DPAT acts on areas other than the DRN and the septum, leading to a decrease in lordosis. Two weeks after implantation with estradiol, the next behavioral test series was carried out after injection with progesterone. Behavioral tests were performed before and after an injection with 10 mg baclofen. The results showed that the mean LQs decreased after the injection in all groups, but the mean LQ in the DRN lesion group was higher than that in the sham groups. These results indicate that baclofen may act partially on the DRN in inhibiting lordosis in female rats.

    DOI PubMed CiNii

  • Effects of 5-HT1A-receptor agonist, 8-OH-DPAT, and GABA(B)-receptor agonist, baclofen, on lordosis in female rats with lesions in either the dorsal raphe nucleus or septum

    M Kishitake, K Yamanouchi

    JOURNAL OF PHARMACOLOGICAL SCIENCES   98 ( 4 ) 419 - 424  2005.08

     View Summary

    The inhibitory effects of 8-OH-DPAT, a 5-HT1A-receptor agonist, and baclofen, a GABA(B)-receptor agonist, on lordosis were examined in estrogen and progesterone-treated ovariectomized rats with lesions in either the dorsal raphe nucleus (DRN) or septum and in rats with either sham lesions or no lesions. The first behavior test series was carried out 6 days after implantation of the rats with silicon tubes containing estradiol. Four hours after injection with 0.5 mg progesterone, behavioral tests were performed before and 30 min after an injection with 1 mg/kg body weight 8-OH-DPAT. As a result, the mean lordosis quotient (LQ)s were changed from 100 to less than 20 before and after the injection in all groups. These results suggest that 8-OH-DPAT acts on areas other than the DRN and the septum, leading to a decrease in lordosis. Two weeks after implantation with estradiol, the next behavioral test series was carried out after injection with progesterone. Behavioral tests were performed before and after an injection with 10 mg baclofen. The results showed that the mean LQs decreased after the injection in all groups, but the mean LQ in the DRN lesion group was higher than that in the sham groups. These results indicate that baclofen may act partially on the DRN in inhibiting lordosis in female rats.

    DOI PubMed CiNii

  • 脳機能の性差-ラットの脳から男と女の脳を考える

    山内兄人

    教育と医学   53 ( 5 ) 422 - 432  2005

  • Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats

    T Kouki, M Okamoto, S Wada, M Kishitake, K Yamanouchi

    BRAIN RESEARCH BULLETIN   64 ( 5 ) 449 - 454  2005.01

     View Summary

    The neural control systems for the ovulatory cycle and lordosis behavior are sexually differentiated by estrogen during the perinatal period in rats. In the present study, the effects of a single neonatal injection with the phytoestrogen, coumestrol, on female reproductive functions were investigated. Female rats were injected subcutaneously with 1 or 3 mg coumestrol (CM1, CM3), 1 mg genistein (GS1), 1 mg estradiol (E-2) or oil at day 5 after birth (birth day = day 1) and an estrous cycle check and lordosis behavior test were performed. As a result, vaginal opening was advanced in CM1-, CM3- or E-2-treated females. A vaginal smear check indicated that oil- or GS1-treated females showed a constant 4- or 5-day estrous cycle, whereas CM1-, CM3- or E2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovary weights in the CM1-, CM3- or E-2-treated groups were lower than those in the oil- and GS1-treated groups and no corpora lutea were found in any rats of these three groups, except for two E-2-treated rats. Behavioral tests were carried out after implantation of E-2-tubes. All rats in the CM1-, GS1-treated groups showed a high lordosis quotient (LQ), being comparable to that in the oil-treated females. On the other hand, LQs in the CM3, E2 or male groups were lower than that in the control female group. These results suggest that a single neonatal injection of 3 mg coumestrol was effective in suppressing the functions of ovulation-inducing mechanisms and the induction of lordosis, but 1 mg coumestrol was effective in only the estrous cycle of female rats. (C) 2004 Elsevier Inc. All rights reserved.

    DOI

  • Sex difference and postnatal change of maternal behavioral patterns in juvenile male and female rats.

    Shima,S, Urano, A, Koranyi, L, Yamanouchi, K

    Zool. Sci.   22 ( 6 ) 695 - 699  2005

    DOI PubMed CiNii

  • Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats

    T Kouki, M Okamoto, S Wada, M Kishitake, K Yamanouchi

    BRAIN RESEARCH BULLETIN   64 ( 5 ) 449 - 454  2005.01

     View Summary

    The neural control systems for the ovulatory cycle and lordosis behavior are sexually differentiated by estrogen during the perinatal period in rats. In the present study, the effects of a single neonatal injection with the phytoestrogen, coumestrol, on female reproductive functions were investigated. Female rats were injected subcutaneously with 1 or 3 mg coumestrol (CM1, CM3), 1 mg genistein (GS1), 1 mg estradiol (E-2) or oil at day 5 after birth (birth day = day 1) and an estrous cycle check and lordosis behavior test were performed. As a result, vaginal opening was advanced in CM1-, CM3- or E-2-treated females. A vaginal smear check indicated that oil- or GS1-treated females showed a constant 4- or 5-day estrous cycle, whereas CM1-, CM3- or E2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovary weights in the CM1-, CM3- or E-2-treated groups were lower than those in the oil- and GS1-treated groups and no corpora lutea were found in any rats of these three groups, except for two E-2-treated rats. Behavioral tests were carried out after implantation of E-2-tubes. All rats in the CM1-, GS1-treated groups showed a high lordosis quotient (LQ), being comparable to that in the oil-treated females. On the other hand, LQs in the CM3, E2 or male groups were lower than that in the control female group. These results suggest that a single neonatal injection of 3 mg coumestrol was effective in suppressing the functions of ovulation-inducing mechanisms and the induction of lordosis, but 1 mg coumestrol was effective in only the estrous cycle of female rats. (C) 2004 Elsevier Inc. All rights reserved.

    DOI

  • Sex difference and postnatal change of maternal behavioral patterns in juvenile male and female rats.

    Shima,S, Urano, A, Koranyi, L, Yamanouchi, K

    Zool. Sci.   22 ( 6 ) 695 - 699  2005

    DOI PubMed CiNii

  • Facilitatory effects of WAY-100635, a 5-HT1A receptor antagonist, on lordosis in female rats

    M Kishitake, K Yamanouchi

    NEUROSCIENCE LETTERS   371 ( 2-3 ) 147 - 151  2004.11

     View Summary

    Effects of the serotonin (5-HT) receptor 1A antagonist, WAY-100635, on lordosis in female rats were examined. Ovariectomized rats were implanted with a silicon tube containing estradiol and behavioural tests were performed. Next, 5, 10 or 20 mg/kg bw WAY-100635 or saline was injected subcutaneously in female rats with a lordosis quotient (LQ) from 10 to 30 and the behavioural test was performed again. As a result, the mean LQs in 10 or 20 mg WAY-100635-treated groups were higher than in the saline-treated group (P < 0.01 and P < 0.05, 10 or 20 mg groups versus saline, respectively). In the experiment on the time-course of change in LQ after injection with 10 mg WAY-100635, the mean LQ was increased (P < 0.01, versus saline) 15 min after the injection and high levels persisted for 1 h. This finding shows that WAY-100635 has the potency to enhance lordosis behaviour acutely in female rats with a low estrous state. In order to investigate relationships between the 5-HT1A receptor and the GABA(B) receptor in regulating lordosis, 10 mg baclofen, a GABA(B) receptor agonist, was injected and this was followed 1 h later by the injection of 10 mg/kg WAY-100635. Mean LQ decreased after the injection of baclofen (P < 0.0001, versus placebo-treated control), but the decrease in LQs was not reversed by injection with WAY-100635. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

    DOI

  • Facilitatory effects of WAY-100635, a 5-HT1A receptor antagonist, on lordosis in female rats

    M Kishitake, K Yamanouchi

    NEUROSCIENCE LETTERS   371 ( 2-3 ) 147 - 151  2004.11

     View Summary

    Effects of the serotonin (5-HT) receptor 1A antagonist, WAY-100635, on lordosis in female rats were examined. Ovariectomized rats were implanted with a silicon tube containing estradiol and behavioural tests were performed. Next, 5, 10 or 20 mg/kg bw WAY-100635 or saline was injected subcutaneously in female rats with a lordosis quotient (LQ) from 10 to 30 and the behavioural test was performed again. As a result, the mean LQs in 10 or 20 mg WAY-100635-treated groups were higher than in the saline-treated group (P < 0.01 and P < 0.05, 10 or 20 mg groups versus saline, respectively). In the experiment on the time-course of change in LQ after injection with 10 mg WAY-100635, the mean LQ was increased (P < 0.01, versus saline) 15 min after the injection and high levels persisted for 1 h. This finding shows that WAY-100635 has the potency to enhance lordosis behaviour acutely in female rats with a low estrous state. In order to investigate relationships between the 5-HT1A receptor and the GABA(B) receptor in regulating lordosis, 10 mg baclofen, a GABA(B) receptor agonist, was injected and this was followed 1 h later by the injection of 10 mg/kg WAY-100635. Mean LQ decreased after the injection of baclofen (P < 0.0001, versus placebo-treated control), but the decrease in LQs was not reversed by injection with WAY-100635. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

    DOI

  • Postnatal apoptosis, development, and sex difference in the lateral septum of rats

    S Tsukahara, K Inami, F Maekawa, M Kakeyama, T Yokoyama, M Yuji, H Kitagawa, Y Kannan, K Yamanouchi

    JOURNAL OF COMPARATIVE NEUROLOGY   475 ( 2 ) 177 - 187  2004.07

     View Summary

    To determine whether apoptosis is involved in the formation of the structure and morphological sex difference of the lateral septum (LS), the postnatal developmental changes in the number of apoptotic cells were examined in the LS on postnatal day 1 (PD1 = birth day), 4, 6, 8, 11, 16, and 31 in male and female rats. Apoptotic cells were imimmohistochemically detected by antibody against single-stranded DNA (ssDNA) or active caspase-3. The volume of the LS was also measured and was found to increase with age. The number of apoptotic cells detected by anti-ssDNA in the LS increased from PD1 to PD8 but decreased after PD11. Also, the LS was divided into dorsal, intermediate, and ventral parts (LSd, LSi, and LSv), and the volume and number of ssDNA-immunoreactive cells in each part were measured on PD6, 8, 11, 16, and 31. In both sexes, a large number of ssDNA-immunoreactive cells was found in the LSd and LSi on PD8 (but not on PD6) and in the LSv on PD6 and PD8. On PD6, the number of active caspase-3-immunoreactive cells was significantly greater in the LSv than in the LSd or LSi, in both sexes. Only the LSi of males had a high number of ssDNA-immunoreacitve cells on PD16; the number was significantly greater than that of females of the same age. However, there was no significant sex difference in the number of active caspase-3-immunoreacitve cells in the LSi on PD16. On PD31, the volume of the LSi was significantly greater in females than in males. There was no sex difference in volume or number of apoptotic cells in the LSd or LSv. These findings indicate that loss of cells due to apoptosis, which is partially caused by activation of caspase-3, occurs in the LS during postnatal development, with regional differences. They also indicate that sex difference in caspase-3-independent apoptosis contributes to morphological sexual differentiation of the LSi. (C) 2004 Wiley-Liss, Tue.

    DOI

  • Postnatal apoptosis, development, and sex difference in the lateral septum of rats

    S Tsukahara, K Inami, F Maekawa, M Kakeyama, T Yokoyama, M Yuji, H Kitagawa, Y Kannan, K Yamanouchi

    JOURNAL OF COMPARATIVE NEUROLOGY   475 ( 2 ) 177 - 187  2004.07

     View Summary

    To determine whether apoptosis is involved in the formation of the structure and morphological sex difference of the lateral septum (LS), the postnatal developmental changes in the number of apoptotic cells were examined in the LS on postnatal day 1 (PD1 = birth day), 4, 6, 8, 11, 16, and 31 in male and female rats. Apoptotic cells were imimmohistochemically detected by antibody against single-stranded DNA (ssDNA) or active caspase-3. The volume of the LS was also measured and was found to increase with age. The number of apoptotic cells detected by anti-ssDNA in the LS increased from PD1 to PD8 but decreased after PD11. Also, the LS was divided into dorsal, intermediate, and ventral parts (LSd, LSi, and LSv), and the volume and number of ssDNA-immunoreactive cells in each part were measured on PD6, 8, 11, 16, and 31. In both sexes, a large number of ssDNA-immunoreactive cells was found in the LSd and LSi on PD8 (but not on PD6) and in the LSv on PD6 and PD8. On PD6, the number of active caspase-3-immunoreactive cells was significantly greater in the LSv than in the LSd or LSi, in both sexes. Only the LSi of males had a high number of ssDNA-immunoreacitve cells on PD16; the number was significantly greater than that of females of the same age. However, there was no significant sex difference in the number of active caspase-3-immunoreacitve cells in the LSi on PD16. On PD31, the volume of the LSi was significantly greater in females than in males. There was no sex difference in volume or number of apoptotic cells in the LSd or LSv. These findings indicate that loss of cells due to apoptosis, which is partially caused by activation of caspase-3, occurs in the LS during postnatal development, with regional differences. They also indicate that sex difference in caspase-3-independent apoptosis contributes to morphological sexual differentiation of the LSi. (C) 2004 Wiley-Liss, Tue.

    DOI

  • Neonatal estrogen decreases neural density of the septum-midbrain central gray connection underlying the lordosis-inhibiting system in female rats

    S Tsukahara, N Ezawa, K Yamanouchi

    NEUROENDOCRINOLOGY   78 ( 4 ) 226 - 233  2003.10

     View Summary

    Neurons in the lateral septum (LS) with projecting axons to the midbrain central gray (MCG) exert an inhibitory influence on lordosis. The number of such neurons is greater in female than in male rats. In this experiment, effects of neonatal estrogen on the density of the LS-MCG connections and on lordosis behavior were examined in female rats. On postnatal day 4 (day 0 = day of birth), females were injected subcutaneously with 50 or 100 mug estradiol benzoate (EB) or oil. On postnatal day 60, females and control males were gonadectomized. Behavioral tests were carried out after the implantation of silicone tubes containing estradiol. Lordotic activities in both males and EB-treated females were lower than in oil-treated females. After completing the behavioral tests, the animals were injected with Fluoro-Gold (FG), a retrograde tracer, into the right-side MCG and the number of FG-labeled neurons in the LS was measured. In all groups, the right-side LS ipsilateral to the FG injection had more FG-labeled neurons than the left-side LS. The number of FG-labeled neurons in the LS of oil-treated females was larger than that of males on both right and left sides. In the females treated with 100 mug EB (EB100), the number of FG-labeled neurons was comparable with that of males and lower than that of oil-treated females. The number of FG-labeled neurons in the EB50 females was also lower than that in oil-treated females, but tended to be larger than that observed in the EB100 group. These results indicate that neonatal estrogen decreases both lordotic activity and the density of the LS-MCG neural connections in female rats. Copyright (C) 2003 S. Karger AG, Basel.

    DOI

  • Neonatal estrogen decreases neural density of the septum-midbrain central gray connection underlying the lordosis-inhibiting system in female rats

    S Tsukahara, N Ezawa, K Yamanouchi

    NEUROENDOCRINOLOGY   78 ( 4 ) 226 - 233  2003.10

     View Summary

    Neurons in the lateral septum (LS) with projecting axons to the midbrain central gray (MCG) exert an inhibitory influence on lordosis. The number of such neurons is greater in female than in male rats. In this experiment, effects of neonatal estrogen on the density of the LS-MCG connections and on lordosis behavior were examined in female rats. On postnatal day 4 (day 0 = day of birth), females were injected subcutaneously with 50 or 100 mug estradiol benzoate (EB) or oil. On postnatal day 60, females and control males were gonadectomized. Behavioral tests were carried out after the implantation of silicone tubes containing estradiol. Lordotic activities in both males and EB-treated females were lower than in oil-treated females. After completing the behavioral tests, the animals were injected with Fluoro-Gold (FG), a retrograde tracer, into the right-side MCG and the number of FG-labeled neurons in the LS was measured. In all groups, the right-side LS ipsilateral to the FG injection had more FG-labeled neurons than the left-side LS. The number of FG-labeled neurons in the LS of oil-treated females was larger than that of males on both right and left sides. In the females treated with 100 mug EB (EB100), the number of FG-labeled neurons was comparable with that of males and lower than that of oil-treated females. The number of FG-labeled neurons in the EB50 females was also lower than that in oil-treated females, but tended to be larger than that observed in the EB100 group. These results indicate that neonatal estrogen decreases both lordotic activity and the density of the LS-MCG neural connections in female rats. Copyright (C) 2003 S. Karger AG, Basel.

    DOI

  • Effects of highly or relatively selective 5-HT1A receptor agonists on lordosis in female rats

    M Kishitake, K Yamanouchi

    ZOOLOGICAL SCIENCE   20 ( 9 ) 1133 - 1138  2003.09

     View Summary

    To investigate the role of serotonin (5-HT) receptor 1 A or 7 in regulating lordosis behavior in female rats, ovariectomized rats were treated with 3 kinds of receptor agonists and lordosis behavior was observed. The injected agents were the selective 5-HT1A receptor agonist, buspirone (BUS), the highly selective 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin ((+/-)8-OH-DPAT), and the 5-HT1A and 5-HT7 receptor agonist, (R)-8-hydroxy-2-(di-n-propylamino)tetralin ((+)8-OH-DPAT). A behavioral test was performed after ovariectomy and subcutaneous implantation of a silicon tube containing estradiol. Female rats in which the lordosis quotient (LQ) was over 70 were intraperitoneally injected with several doses of these agents. As a result, in the BUS group, the dose of 3 mg/kg bw, but not 1 mg/kg was effective for suppressing lordosis. On the other hand, an inhibitory effect was observed from 0.25 mg/kg and 0.5 mg/kg in the (+)8-OH-DPAT and ()8-OH-DPAT groups, respectively. In the time-course experiment, in all drug-treated groups, LQ decreased to lower than 20 after 15 min and low LQ continued for 1 hr at least. Measurement of locomotor activity using an infrared sensor system showed no relation between the decrease in lordosis by these agents and spontaneous locomotion. These results indicate that 5-HT1A is strongly involved in the lordosis-inhibiting circuit of the serotonin neurons.

    DOI PubMed CiNii

  • Effects of highly or relatively selective 5-HT1A receptor agonists on lordosis in female rats

    M Kishitake, K Yamanouchi

    ZOOLOGICAL SCIENCE   20 ( 9 ) 1133 - 1138  2003.09

     View Summary

    To investigate the role of serotonin (5-HT) receptor 1 A or 7 in regulating lordosis behavior in female rats, ovariectomized rats were treated with 3 kinds of receptor agonists and lordosis behavior was observed. The injected agents were the selective 5-HT1A receptor agonist, buspirone (BUS), the highly selective 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin ((+/-)8-OH-DPAT), and the 5-HT1A and 5-HT7 receptor agonist, (R)-8-hydroxy-2-(di-n-propylamino)tetralin ((+)8-OH-DPAT). A behavioral test was performed after ovariectomy and subcutaneous implantation of a silicon tube containing estradiol. Female rats in which the lordosis quotient (LQ) was over 70 were intraperitoneally injected with several doses of these agents. As a result, in the BUS group, the dose of 3 mg/kg bw, but not 1 mg/kg was effective for suppressing lordosis. On the other hand, an inhibitory effect was observed from 0.25 mg/kg and 0.5 mg/kg in the (+)8-OH-DPAT and ()8-OH-DPAT groups, respectively. In the time-course experiment, in all drug-treated groups, LQ decreased to lower than 20 after 15 min and low LQ continued for 1 hr at least. Measurement of locomotor activity using an infrared sensor system showed no relation between the decrease in lordosis by these agents and spontaneous locomotion. These results indicate that 5-HT1A is strongly involved in the lordosis-inhibiting circuit of the serotonin neurons.

    DOI PubMed CiNii

  • Effects of neonatal treatment with phytoestrogens, genistein and daidzein, on sex difference in female rat brain function: estrous cycle and lordosis

    T Kouki, M Kishitake, M Okamoto, Oosuka, I, M Takebe, K Yamanouchi

    HORMONES AND BEHAVIOR   44 ( 2 ) 140 - 145  2003.08

     View Summary

    It is well known that neonatal exposure to estrogen induces masculinization or defeminization of the brain. In this study, the effects of neonatal treatment with two kinds of soybean isoflavone aglycone, genistein (GS) and daidzein (DZ), on the estrous cycle and lordosis behavior were investigated. Female rats were injected subcutaneously with 1 mg GS, 1 mg DZ, 100 mug estradiol (E-2), or oil daily for 5 days from birth. As a result, vaginal opening was advanced in GS- or E-2-treated females. A vaginal smear check indicated that oil- or DZ-treated females showed a constant 4- or 5-day estrous cycle, whereas GS- or E-2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovaries in the GS- or E-2-treated groups were smaller than those in the oil- and DZ-treated groups and contained no corpora lutea. In the DZ group, although corpora lutea were seen, ovaries were smaller than that of control females. Behavioral tests were carried out after implantation of E-2-tubes. All of the oil- or DZ-treated females showed lordosis with a high lordosis quotient (LQ). On the other hand, as male rats, LQs were extremely low in the E-2-treated group, when compared to the oil-treated group. In the GS-treated group, the mean LQ was lower than that in the oil-treated group, but higher than those in the E-2-treated female or male groups. These results suggest that genistein acts as an estrogen in the sexual differentiation of the brain and causes defeminization of the brain in regulating lordosis and the estrous cycle in rats. In addition, neonatal daidzein also has some influence on ovarian function. (C) 2003 Elsevier Inc. All rights reserved.

    DOI

  • Effects of neonatal treatment with phytoestrogens, genistein and daidzein, on sex difference in female rat brain function: estrous cycle and lordosis

    T Kouki, M Kishitake, M Okamoto, Oosuka, I, M Takebe, K Yamanouchi

    HORMONES AND BEHAVIOR   44 ( 2 ) 140 - 145  2003.08

     View Summary

    It is well known that neonatal exposure to estrogen induces masculinization or defeminization of the brain. In this study, the effects of neonatal treatment with two kinds of soybean isoflavone aglycone, genistein (GS) and daidzein (DZ), on the estrous cycle and lordosis behavior were investigated. Female rats were injected subcutaneously with 1 mg GS, 1 mg DZ, 100 mug estradiol (E-2), or oil daily for 5 days from birth. As a result, vaginal opening was advanced in GS- or E-2-treated females. A vaginal smear check indicated that oil- or DZ-treated females showed a constant 4- or 5-day estrous cycle, whereas GS- or E-2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovaries in the GS- or E-2-treated groups were smaller than those in the oil- and DZ-treated groups and contained no corpora lutea. In the DZ group, although corpora lutea were seen, ovaries were smaller than that of control females. Behavioral tests were carried out after implantation of E-2-tubes. All of the oil- or DZ-treated females showed lordosis with a high lordosis quotient (LQ). On the other hand, as male rats, LQs were extremely low in the E-2-treated group, when compared to the oil-treated group. In the GS-treated group, the mean LQ was lower than that in the oil-treated group, but higher than those in the E-2-treated female or male groups. These results suggest that genistein acts as an estrogen in the sexual differentiation of the brain and causes defeminization of the brain in regulating lordosis and the estrous cycle in rats. In addition, neonatal daidzein also has some influence on ovarian function. (C) 2003 Elsevier Inc. All rights reserved.

    DOI

  • Distribution of glutamic acid decarboxylase, neurotensin, enkephalin, neuropeptide Y , and cholccystokinin neurons in the septo-preoptic region of male rats.

    Tsukahra,S, Yamanouchi,K

    J. Reprod. Develop.   49 ( 1 ) 67 - 77  2003

    DOI PubMed CiNii

  • Distribution of glutamic acid decarboxylase, neurotensin, enkephalin, neuropeptide Y , and cholccystokinin neurons in the septo-preoptic region of male rats.

    Tsukahra,S, Yamanouchi,K

    J. Reprod. Develop.   49 ( 1 ) 67 - 77  2003

    DOI PubMed CiNii

  • 勃起のメカニズム(男性ホルモンの関与も含めて)

    山内兄人

    日本臨床:増刊(男性機能不全―ED関連の基礎・臨床研究の進歩   60   65 - 70  2002

  • Sex difference in septal neurons projecting Axons to midbrain central gray in rats: A combined double retrograde tracing and ER-immunohistochemical study

    S Tsukahara, K Yamanouchi

    ENDOCRINOLOGY   143 ( 1 ) 285 - 294  2002.01

     View Summary

    Sex difference in the number of neurons projecting axons from the lateral septum (LS) to the midbrain central gray (MCG) that are concerned with the lordosis-inhibiting system was investigated by injection of Fluoro-Gold (FG), a retrograde tracer, into the rostral MCG on the right side in male and female rats. Immunohistochemistry for ER-alpha and -beta was also performed with or without combination with FG immunostaining. All animals were gonadectomized. Lordosis was observed after treatment with E2 in some animals. In the results, lordosis was rare in males, compared with females. FG-immunoreactive (ir) cells were concentrated in the intermediate LS on the right side, and its number in the females was significantly higher than that in the males. There was no sex difference in the distribution and number of ERalpha-ir and ERbeta-ir cells in the LS. Furthermore, the number of ERs-ir cells was not influenced by E2 in either males or females. Double FG-ERbeta-ir cells were less than 20% of total FG-ir cells in the LS in both males and females. These data suggest that the LS-MCG connection is sexually dimorphic but that there is no sex difference in the expression of ERs in the LS.

    DOI

  • Decrease of serotonin and metabolite in the forebrain and facilitation of lordosis by dorsal raphe nucleus lesions in male rats

    Kakeyama, M, Umino, A, Nishikawa, T, Yamanouchi, K

    Endocr. J.   49 ( 5 ) 573 - 579  2002

    DOI PubMed CiNii

  • Sex difference in septal neurons projecting Axons to midbrain central gray in rats: A combined double retrograde tracing and ER-immunohistochemical study

    S Tsukahara, K Yamanouchi

    ENDOCRINOLOGY   143 ( 1 ) 285 - 294  2002.01

     View Summary

    Sex difference in the number of neurons projecting axons from the lateral septum (LS) to the midbrain central gray (MCG) that are concerned with the lordosis-inhibiting system was investigated by injection of Fluoro-Gold (FG), a retrograde tracer, into the rostral MCG on the right side in male and female rats. Immunohistochemistry for ER-alpha and -beta was also performed with or without combination with FG immunostaining. All animals were gonadectomized. Lordosis was observed after treatment with E2 in some animals. In the results, lordosis was rare in males, compared with females. FG-immunoreactive (ir) cells were concentrated in the intermediate LS on the right side, and its number in the females was significantly higher than that in the males. There was no sex difference in the distribution and number of ERalpha-ir and ERbeta-ir cells in the LS. Furthermore, the number of ERs-ir cells was not influenced by E2 in either males or females. Double FG-ERbeta-ir cells were less than 20% of total FG-ir cells in the LS in both males and females. These data suggest that the LS-MCG connection is sexually dimorphic but that there is no sex difference in the expression of ERs in the LS.

    DOI

  • Decrease of serotonin and metabolite in the forebrain and facilitation of lordosis by dorsal raphe nucleus lesions in male rats

    Kakeyama, M, Umino, A, Nishikawa, T, Yamanouchi, K

    Endocr. J.   49 ( 5 ) 573 - 579  2002

    DOI PubMed CiNii

  • Neurohistological and behavioral evidence for lordosis-inhibiting tract from lateral septum to periaqueductal gray in male rats

    Shinji Tsukahara, Korehito Yamanouchi

    Journal of Comparative Neurology   431 ( 3 ) 293 - 310  2001.03

     View Summary

    To verify the anatomical and functional connection of the lateral septum (LS) and periaqueductal gray (PAG) in inhibiting female sexual behavior, lordosis, in male rats, retrograde (Fluoro-Gold, FG) or anterograde (Phaseolus vulgaris-leucoagglutinin, PHA-L) tracer was injected into the PAG or LS on the right side, respectively, and FG-labeled cells or PHA-L-labeled axons in the forebrain and mesencephalon were determined in estrogen-treated castrated male rats. A ventral cut (VC) of the septum and a behavioral test were also conducted in some FG-injected rats. Furthermore, lordosis behavior was observed after chemical destruction of the septum by ibotenate. As a result, the lordosis quotient (LQ) in VC males was higher than that in control males without VC. FG-labeled neuronal cell bodies were found in the ipsilateral intermediate part of the LS in the control males but not in this area of the VC males. When neuronal cells in the intermediate part of the bilateral LS were completely destroyed by ibotenate, the LQ was higher than that in sham-lesioned male rats. These results suggest that a direct neural connection of the intermediate LS to the PAG has an inhibitory role in regulating lordosis in male rats. In addition, neuronal cell bodies in the intermediate LS exert an inhibitory influence. In the PHA-L experiment, labeled axons were seen in the ventral part of the LS, the medial forebrain bundle at the chiasmatic level, the lateral hypothalamus, the median region of the mesencephalon, and the rostral PAG in the side ipsilateral to the tracer injection site of the LS. Thus, these areas are thought to be involved in the pathway for lordosis-inhibition from the intermediate part of the LS to the PAG in male rats. © 2001 Wiley-Liss, Inc.

    DOI PubMed

  • 脳と性行動

    山内兄人

    日本性科学会誌   19   3 - 11  2001

  • Neurohistological and behavioral evidence for lordosis ミinhibiting tract from lateral septum to periaqueductal gray in male rats

    Tsukahara, S, Yamanouchi, K

    J. Comp. Neurol   431 ( 3 ) 293 - 610  2001

    DOI

  • Inhibitory effect of dorsal cut of hypothalamus on ovulation delayed by pentobarbital in female rat

    Watanabe,M, Yamanouchi, K

    J. Reprod. Develop.   47 ( 5 ) 253 - 258  2001

    DOI CiNii

  • Inhibitory effect of postpartum lesions or cuts in median raphe nucleus on maternal behavior in female rats

    Yurino, H, Tsukahara, S, Korany, L, Yamanocuchi, K

    Zool. Sci   18 ( 9 ) 1225 - 1230  2001

    DOI PubMed CiNii

  • Inhibitory effect of dorsal cut of hypothalamus on ovulation delayed by pentobarbital in female rat

    Watanabe,M, Yamanouchi, K

    J. Reprod. Develop.   47 ( 5 ) 253 - 258  2001

    DOI CiNii

  • Inhibitory effect of postpartum lesions or cuts in median raphe nucleus on maternal behavior in female rats

    Yurino, H, Tsukahara, S, Korany, L, Yamanocuchi, K

    Zool. Sci   18 ( 9 ) 1225 - 1230  2001

    DOI PubMed CiNii

  • Lordosis-inhibiting effect of progesterone in male and female rats with septal lesions

    M Satou, K Yamanouchi

    BRAIN RESEARCH BULLETIN   53 ( 3 ) 331 - 334  2000.10

     View Summary

    The inhibitory role of progesterone (P) in regulating lordosis was investigated in male and female rats with septal lesions (SL). Male rats with SL showed lordosis quotients (LO) as high as female rats with SL and female control rats without brain surgery after injection of 50 mug/kg estradiol benzoate (EB) followed by 0.5 mg P 44 h later. Even when primed with 5 mg P 1 h prior to the 50 mug EB-injection, the mean LQs were still high in all groups. When the dose of EB was decreased to 5 mug/kg, all rats showed high-score LQs. In contrast, all animals in both male and female in which 5 mg P was injected 1 h before 5 mug EB, showed low LQs. These results suggest that P is effective in suppressing lordosis enhanced by estrogen in either male rats or females. Furthermore, the high dose of estrogen overcomes the inhibitory action of P on lordosis in both sexes. (C) 2000 Elsevier Science Inc.

    DOI

  • Acceleration of mounting behaviors in female rats by ibotenic acid lesions in the ventromedial hypothalamic nucleus

    Takahiro Matsumoto, Korehito Yamanouchi

    Neuroscience Letters   291 ( 3 ) 143 - 146  2000.09

     View Summary

    To clarify the role of the ventromedial (VMH) or dorsomedial (DMH) hypothalamic nucleus in regulating male sexual behavior in female rats, radiofrequency or ibotenic acid lesions were made in ovariectomized rats, and three behavioral tests in total were carried out after implantation of Silastic tubes containing testosterone. As a result, females with radiofrequency or ibotenic acid lesions in the VMH showed higher levels of mounting behavior than those in females with no brain surgery or with sham-operation. The incidence of intromissive pattern in females with ibotenic acid lesions but not in females with radiofrequency lesions was higher than those in other female control groups. In the group of radiofrequency lesions in the DMH, both frequencies of mounting and intromissive pattern were lower than those in control and sham groups. No ejaculatory pattern was seen in any of the female groups. These results indicate that neuronal cell bodies in the VMH, but not in the DMH, exert an inhibitory influence on mounting activity in female rats. © 2000 Elsevier Science Ireland Ltd.

    DOI PubMed

  • Acceleration of mounting behaviors in female rats by ibotenic acid lesions in the ventromedial hypothalamic nucleus

    T Matsumoto, K Yamanouchi

    NEUROSCIENCE LETTERS   291 ( 3 ) 143 - 146  2000.09

     View Summary

    To clarify the role of the ventromedial (VMH) or dorsomedial (DMH) hypothalamic nucleus in regulating male sexual behavior in female rats, radiofrequency or ibotenic acid lesions were made in ovariectomized rats, and three behavioral tests in total were carried out after implantation of Silastic tubes containing testosterone. As a result, females with radiofrequency or ibotenic acid lesions in the VMH showed higher levels of mounting behavior than those in females with no brain surgery or with sham-operation. The incidence of intromissive pattern in females with ibotenic acid lesions but not in females with radiofrequency lesions was higher than those in other female control groups. In the group of radiofrequency lesions in the DMH, both frequencies of mounting and intromissive pattern were lower than those in control and sham groups. No ejaculatory pattern was seen in any of the female groups. These results indicate that neuronal cell bodies in the VMH, but not in the DMH, exert an inhibitory influence on mounting activity in female rats. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.

    DOI

  • 性行動神経制御におけるエストロゲンの作用と性分化

    山内兄人, 塚原伸治

    自律神経   37 ( 2 ) 221 - 228  2000

  • 雌ラット中枢神経系における雌型性行動制御機構:中隔外側核の抑制機構を中心として

    塚原伸治, 山内兄人

    日本性機能学会誌   15 ( 3 ) 343 - 352  2000

  • 脳の性機能と性差

    山内兄人

    21世紀フォーラム   72   50 - 59  2000

  • 性行動と性分化

    山内兄人

    埼玉医科大学雑誌   27 ( 1 ) 59 - 69  2000

  • Decrease of sexual receptivity by prolylendopeptidase inhibitor in female rats.

    Oosuka I, Tanaka, Y, Miura N, Yamanouchi, K

    Jpn.J. Pharmacol.   83 ( 1 ) 82 - 85  2000

    DOI PubMed CiNii

  • Suppression of spontaneous ovulation by interruption of dorsal input of hypothalamus at various timings during rat estrous cycle

    Miho Watanabe, Korehito Yamanouchi

    Journal of Reproduction and Development   46 ( 1 ) 39 - 45  2000

     View Summary

    To clarify the role of the extrahypothalamic input to the preoptic area (POA)-medial basal hypothalamus (MBH) on spontaneous ovulation, the dorsal cut of the POA-MBH was performed on various days and ova were counted in female rats. An anterior half-circle cut (anterior dorsal cut
    ADC) was performed at the dorsal of the POA on the day of proestrus. As a result, ovulation was seen on the day of estrus when ADC was performed in the evening (18:00-19:30 h) but did not occur when performed in the morning (10:00-11:30 h). Furthermore, the suppressive effect of ADC was observed, even when cut was performed in the evening 2-5 days before estrus. These results suggest that the dorsal input to the POA-MBH plays an important role in ovulation-triggering mechanisms. In addition, about 7 days after the ADC, regular estrous cycle and normal ovulation were seen. Furthermore, destruction of the medial or bilateral lateral septum was done in the morning of proestrus, to investigate the role of gonadotropin-releasing hormone (GnRH) neurons in these areas. Lesions in the septal area had no effect, suggesting that the inhibitory effect on ovulation of the ADC is not due to interruption of the fibers of the septum including GnRH neurons.

    DOI CiNii

  • Lordosis-inhibiting effect of progesterone in male and female rats with septal lesions.

    Satou, M, Yamanouchi, K

    Brain Res. Bull.   53 ( 3 ) 331 - 334  2000

    DOI

  • Decrease of sexual receptivity by prolylendopeptidase inhibitor in female rats.

    Oosuka I, Tanaka, Y, Miura N, Yamanouchi, K

    Jpn.J. Pharmacol.   83 ( 1 ) 82 - 85  2000

    DOI PubMed CiNii

  • Suppression of spontaneous ovulation by interruption of dorsal input of hypothalamus at various timings during rat estrous cycle

    Miho Watanabe, Korehito Yamanouchi

    Journal of Reproduction and Development   46 ( 1 ) 39 - 45  2000

     View Summary

    To clarify the role of the extrahypothalamic input to the preoptic area (POA)-medial basal hypothalamus (MBH) on spontaneous ovulation, the dorsal cut of the POA-MBH was performed on various days and ova were counted in female rats. An anterior half-circle cut (anterior dorsal cut
    ADC) was performed at the dorsal of the POA on the day of proestrus. As a result, ovulation was seen on the day of estrus when ADC was performed in the evening (18:00-19:30 h) but did not occur when performed in the morning (10:00-11:30 h). Furthermore, the suppressive effect of ADC was observed, even when cut was performed in the evening 2-5 days before estrus. These results suggest that the dorsal input to the POA-MBH plays an important role in ovulation-triggering mechanisms. In addition, about 7 days after the ADC, regular estrous cycle and normal ovulation were seen. Furthermore, destruction of the medial or bilateral lateral septum was done in the morning of proestrus, to investigate the role of gonadotropin-releasing hormone (GnRH) neurons in these areas. Lesions in the septal area had no effect, suggesting that the inhibitory effect on ovulation of the ADC is not due to interruption of the fibers of the septum including GnRH neurons.

    DOI CiNii

  • Effect of direct application of estrogen aimed at lateral septum or dorsal raphe nucleus on lordosis behavior: Regional and sexual differences in rats

    M Satou, K Yamanouchi

    NEUROENDOCRINOLOGY   69 ( 6 ) 446 - 452  1999.06

     View Summary

    The role of estrogen in lordosis-inhibiting systems in the lateral septum or the dorsal raphe nucleus was investigated in female and male rats. Ovariectomized rats received implantation of 22-gauge guide cannulae to the bilateral or right side of the lateral septum (LS and rLS, respectively), the dorsal raphe nucleus (DRN) or bilateral cortex (CX). In castrated male rats, bilateral implantations of the cannulae to the LS were carried out (mLS). Three behavioral tests in total were performed at 2-week intervals. In the first test, all animals were subcutaneously injected with 1.5 mu g/kg estradiol benzoate (EB). Forty-four hours after EB, 0.5 mg progesterone (P) was injected and a behavioral test was started 4 h after P. These hormonal regimes were used in all tests. In the second test, 2 h before EB injection, 27-gauge cannulae filled with estradiol (E-2) were inserted into the DRN, LS or CX through the guide cannulae and were kept there for 4 h. In the third test, cholesterol was implanted instead of Eg into these areas. In the first test, most females showed low levels of lordosis quotient (LQ) and most males showed no lordosis. In the second test, mean LQs in the LS or rLS groups of females increased but not in the DRN and CX groups. In the mLS group no increase of LQ was observed. When cholesterol was implanted in the third test, mean LQs in all groups were as low as in the first test. These results suggest the possibility that estrogen releases the inhibition when it acts on the LS, but not on the DRN female rats. On the other hand, inhibition in the male LS may not be released by the direct action of estrogen.

    DOI

  • ペントバルビタールによる排卵遅延:雌ラット視床下部背側部神経線維切断効果

    渡部美穂, 山内兄人

    日本内分泌学会誌   75 ( 2 ) 401  1999

  • 性ホルモンと運動:中枢神経系の性分化

    山内兄人

    ヒューマンサイエンス   11 ( 2 ) 4 - 8  1999

  • Prevention of inhibitory effect of dorsal raphe nucleus lesions on ovulation and LH surge by 5-HT 2A/2C receptor agonists in female rats.

    Maekawa,f, Tsukahara,S, Tsukamura,H, Maeda、k-I, Yamanouchi,K

    Neurosci. Res.   35 ( 4 ) 291 - 298  1999

    DOI PubMed CiNii

  • Prevention of inhibitory effect of dorsal raphe nucleus lesions on ovulation and LH surge by 5-HT 2A/2C receptor agonists in female rats.

    Maekawa,f, Tsukahara,S, Tsukamura,H, Maeda、k-I, Yamanouchi,K

    Neurosci. Res.   35 ( 4 ) 291 - 298  1999

    DOI PubMed CiNii

  • Effect of direct application of estrogen aimed at lateral septum or dorsal raphe nucleus on lordosis behavior: Regional and sexual differences in rats

    Motoyasu Satou, Korehito Yamanouchi

    Neuroendocrinology   69 ( 6 ) 446 - 452  1999

     View Summary

    The role of estrogen in lordosis-inhibiting systems in the lateral septum or the dorsal raphe nucleus was investigated in female and male rats. Ovariectomized rats received implantation of 22-gauge guide cannulae to the bilateral or right side of the lateral septum (LS and rLS, respectively), the dorsal raphe nucleus (DRN) or bilateral cortex (CX). In castrated male rats, bilateral implantations of the cannulae to the LS were carried out (mLS). Three behavioral tests in total were performed at 2-week intervals. In the first test, all animals were subcutaneously injected with 1.5 μg/kg estradiol benzoate (EB). Forty-four hours after EB, 0.5 mg progesterone (P) was injected and a behavioral test was started 4 h after P. These hormonal regimes were used in all tests. In the second test, 2 h before EB injection, 27-gauge cannulae filled with estradiol (E2) were inserted into the DRN, LS or CX through the guide cannulae and were kept there for 4 h. In the third test, cholesterol was implanted instead of E2 into these areas. In the first test, most females showed low levels of lordosis quotient (LQ) and most males showed no lordosis. In the second test, mean LQs in the LS or rLS groups of females increased but not in the DRN and CX groups. In the mLS group no increase of LQ was observed. When cholesterol was implanted in the third test, mean LQs in all groups were as low as in the first test. These results suggest the possibility that estrogen releases the inhibition when it acts on the LS, but not on the DRN female rats. On the other hand, inhibition in the male LS may not be released by the direct action of estrogen.

    DOI PubMed

  • Inhibitory effect of neural transections of dorsal raphe nucleus on induction of nocturnal prolactin surge by vaginal stimulation in ovariectomized rats

    F Maekawa, S Tsukahara, K Tsukamura, KI Maeda, K Yamanouchi

    BRAIN RESEARCH   813 ( 1 ) 195 - 199  1998.11

     View Summary

    The effect of complete (CC), anterior (AC) or posterior (PC) cut of the dorsal raphe nucleus (DRn) on induction of the nocturnal prolactin (PRL) surge by electrical vaginal stimulation (VS) was investigated in ovariectomized rats. Plasma level of PRL was measured by radioimmunoassay before and after VS. The data revealed that PRL levels increased in early morning on the day following VS in the rats without brain surgery or with sham-operation. In contrast, the nocturnal PRL surge did not occur in the CC, AC, or PC rats. These results suggest that both the anterior and the posterior fibers of the DRn plays an important role in induction of nocturnal PRL surge by VS in ovariectomized rats. (C) 1998 Elsevier Science B.V. All rights reserved.

    DOI PubMed CiNii

  • Inhibitory effect of neural transections of dorsal raphe nucleus on induction of nocturnal prolactin surge by vaginal stimulation in ovariectomized rats

    F Maekawa, S Tsukahara, K Tsukamura, KI Maeda, K Yamanouchi

    BRAIN RESEARCH   813 ( 1 ) 195 - 199  1998.11

     View Summary

    The effect of complete (CC), anterior (AC) or posterior (PC) cut of the dorsal raphe nucleus (DRn) on induction of the nocturnal prolactin (PRL) surge by electrical vaginal stimulation (VS) was investigated in ovariectomized rats. Plasma level of PRL was measured by radioimmunoassay before and after VS. The data revealed that PRL levels increased in early morning on the day following VS in the rats without brain surgery or with sham-operation. In contrast, the nocturnal PRL surge did not occur in the CC, AC, or PC rats. These results suggest that both the anterior and the posterior fibers of the DRn plays an important role in induction of nocturnal PRL surge by VS in ovariectomized rats. (C) 1998 Elsevier Science B.V. All rights reserved.

    DOI PubMed CiNii

  • Inhibitory effect of progesterone on androgen-induced lordosis in ovariectomized rats

    M Satou, K Yamanouchi

    ENDOCRINE JOURNAL   45 ( 2 ) 235 - 239  1998.04

     View Summary

    Androgen has a potency to induce female sexual behavior in ovariectomized rats. This study investigated the inhibitory effect of progesterone (P) on lordosis behavior facilitated by androgen. Ovariectomized female rats were given 100 to 800 mu g/kg testosterone propionate (TP) or 5 mu g/kg estradiol benzoate (EB). Forty-four hours after administration of the TP or the EB, all females received 0.5 mg P, and the first behavioral test was carried out four hours later. TP-treated animals showed lordosis responses in a dose dependent manner. Two weeks after the first test, the animals were retested by using the same hormonal regime as in the first test, except that an additional 5 mg P was administered 1 h prior to the TP or the EB. As a result, significant reductions in sexual receptivity were observed in the TP-treated as well as in the EB-treated females. These results indicate that progesterone can inhibit androgen-induced lordosis behavior in female rats.

    DOI PubMed CiNii

  • ラットの性行動と性分化における性ホルモンの働き

    山内兄人

    遺伝   2 ( 10 ) 70 - 75  1998

  • 雌ラットの性行動と性ホルモン

    佐藤元康, 山内兄人

    Hormone Frontier In Gynecology   5 ( 3 ) 297 - 304  1998

  • 性行動制御機構とその性分化における性ホルモンの役割

    山内兄人, 佐藤元康

    神経研究の進歩(特集、脳とステロイドホルモン)   42 ( 4 ) 610 - 623  1998

    DOI

  • Inhibitory pathway for female sexual behavior in male rat brain: Effectof medial forebrain bundle (MFB) cuts

    Yamashita-Suzuki, K, Yamanouchi, K

    J. Reprod. Develop.   44 ( 4 ) 393 - 398  1998

    DOI CiNii

  • Differential effects of dorsal raphe nucleus lesions on pseudopregnfancy induced by reserpine or vaginal stimulation in female rats.

    Maekawa,F, Yamanouchi,K

    J. Reprod. Develop.   44 ( 4 ) 337 - 343  1998

    DOI CiNii

  • Inhibitory pathway for female sexual behavior in male rat brain: Effectof medial forebrain bundle (MFB) cuts

    Yamashita-Suzuki, K, Yamanouchi, K

    J. Reprod. Develop.   44 ( 4 ) 393 - 398  1998

    DOI CiNii

  • Differential effects of dorsal raphe nucleus lesions on pseudopregnfancy induced by reserpine or vaginal stimulation in female rats.

    Maekawa,F, Yamanouchi,K

    J. Reprod. Develop.   44 ( 4 ) 337 - 343  1998

    DOI CiNii

  • Inhibitory effect of progesterone on androgen-induced lordosis in ovariectomized rats.

    Satou, M, Yamanouchi, K

    Endocrine J.   45 ( 2 ) 235 - 239  1998

    DOI PubMed CiNii

  • Potentiation of ejaculatory activity by median raphe nucleus lesions in male rats: Effect of p-chlorophenylalanine

    Y Kondo, K Yamanouchi

    ENDOCRINE JOURNAL   44 ( 6 ) 873 - 879  1997.12

     View Summary

    The effect of radiofrequency lesions in the median or dorsal raphe nucleus (MRL or DRL) on copulatory behavior was examined in sexually inexperienced male rats. Three weeks after castration and the brain surgery, all males were subcutaneously implanted with Silastic capsules containing testosterone. In the first behavioral test, the frequency of ejaculation in the MRL group was significantly higher than that in sham and DRL males, but mount and intromission were not. Seven days after the first test, the second test was carried out after treatments with 100 mg/kg p-chlorophenylalanine (PCPA), a serotonin synthesis inhibitor, or saline daily for 4 days in MRL and DRL males. The frequencies of male sexual behavior in PCPA treated DRL males were higher than those in saline treated DRL males. In contrast, even after treatments with PCPA, male sexual activity in MRL males was comparable to those in saline treated MRL males. These results suggest that serotonergic neurons in the median raphe nucleus play an inhibitory role in the regulation of male sexual activity, especially ejaculation. Furthermore, it can be thought that PCPA acts on the median raphe neurons and facilitates ejaculatory behavior.

    DOI PubMed CiNii

  • Potentiation of ejaculatory activity by median raphe nucleus lesions in male rats: Effect of p-chlorophenylalanine

    Y Kondo, K Yamanouchi

    ENDOCRINE JOURNAL   44 ( 6 ) 873 - 879  1997.12

     View Summary

    The effect of radiofrequency lesions in the median or dorsal raphe nucleus (MRL or DRL) on copulatory behavior was examined in sexually inexperienced male rats. Three weeks after castration and the brain surgery, all males were subcutaneously implanted with Silastic capsules containing testosterone. In the first behavioral test, the frequency of ejaculation in the MRL group was significantly higher than that in sham and DRL males, but mount and intromission were not. Seven days after the first test, the second test was carried out after treatments with 100 mg/kg p-chlorophenylalanine (PCPA), a serotonin synthesis inhibitor, or saline daily for 4 days in MRL and DRL males. The frequencies of male sexual behavior in PCPA treated DRL males were higher than those in saline treated DRL males. In contrast, even after treatments with PCPA, male sexual activity in MRL males was comparable to those in saline treated MRL males. These results suggest that serotonergic neurons in the median raphe nucleus play an inhibitory role in the regulation of male sexual activity, especially ejaculation. Furthermore, it can be thought that PCPA acts on the median raphe neurons and facilitates ejaculatory behavior.

    DOI PubMed CiNii

  • Lordosis in male rats: Effect of dorsal raphe nucleus cuts

    M Kakeyama, K Yamanouchi

    HORMONES AND BEHAVIOR   32 ( 1 ) 60 - 67  1997.08

     View Summary

    The efferents and/or afferents of the dorsal raphe nucleus (DRN) were transected by several types of cut in castrated male rats, and lordosis behavior was observed after implantation with Silastic tubes containing estradiol. Throughout the behavioral tests, low incidences of lordosis were observed in control male rats without brain surgery or with a sham operation. in contrast, all male rats with a horizontal circle cut at the ventral area of the DRN displayed lordosis, and the mean lordosis quotient (LQ) was higher than that in control rats, while rats with a horizontal cut at the dorsal area of the DRN did not. Furthermore, mean LQs in male rats with an anterior half-circle horizontal cut at the ventral area of the DRN were higher than those in control groups. A posterior half-circle cut at the ventral area had no effect. In addition, male rats with a half-dome cut located anterior to the DRN showed a high LQ score, but rats with a posterior half-dome cut did not. These results suggest that anterior and anteroventral neural fibers of the DRN are involved in the lordosis inhibiting mechanism in male rats. (C) 1997 Academic Press.

    DOI

  • Effects of p-chlorophenylalanine on male sexual behavior in female rats with mesencephalic raphe nuclei lesions

    T Matsumoto, K Yamanouchi

    ENDOCRINE JOURNAL   44 ( 3 ) 383 - 388  1997.06

     View Summary

    The role of serotonergic neurons in the mesencephalic raphe nuclei in regulating male sexual behavior in female rats was examined. The median or dorsal raphe nucleus lesions (MRL or DRL) were made in ovariectomized rats and behavioral tests were performed after implantation of Silastic tubes containing testosterone and treatment with serotonin synthesis inhibitor p-chlorophenylalanine (pCPA). Half of the animals in each group received 4 100 mg/kg pCPA injections before the behavioral test. As a result, the incidences and frequencies of mounts and intromissive patterns in the MRL and DRL groups were comparable to those in control females without brain surgery. Mount latency in the MRL females was shorter than that in the control females. When pCPA was given, most females with or without brain surgery showed mounts and intromissive patterns, and frequencies were higher than those in females without pCPA. These results suggest that the median raphe nucleus plays an inhibitory role in the onset mechanism for mounting. On the other hand, a stronger inhibitory influence in regulating male sexual behavior exists in other serotonergic neurons than those in the median and dorsal raphe nuclei in female rats.

    DOI PubMed CiNii

  • Effects of p-chlorophenylalanine on reflexive and noncontact penile erections in male rats

    T Matsumoto, Y Kondo, BD Sachs, K Yamanouchi

    PHYSIOLOGY & BEHAVIOR   61 ( 2 ) 165 - 168  1997.02

     View Summary

    To clarify the role of serotonin in penile erection, testosterone-primed castrated male rats were treated with the serotonin-synthesis inhibitor, p-chlorophenylalanine (pCPA), and reflexive erection (RE; male supine, penile sheath retracted) and noncontact erection (NCE; penile erection evoked by remote sexual stimuli) tests were performed. Half the males were injected with 100 mg/kg pCPA 4 times before each test; control males were treated with saline instead of pCPA. In the RE test, compared to the control group, pCPA-treated males had a shorter erection latency, but they also displayed fewer erections. NCE tests were conducted as a 2 x 2 factorial experiment: pCPA or saline, and estrous female present or absent. Only the pCPA-female Group had a high proportion of responders (68%), compared to 14-27% in the other Groups (p < 0.02). These results suggest that the serotonergic system exerts facilitative and inhibitory influences on different systems in regulating reflexive erection. On the other hand, serotonin appears to play an inhibitory role in the induction of noncontact erection, because pCPA did not directly induce erection, but rather facilitated the response to females. Copyright (C) 1997 Elsevier Science Inc.

    DOI

  • Effects of p-chlorophenylalanine on reflexive and noncontact penile erections in male rats

    T Matsumoto, Y Kondo, BD Sachs, K Yamanouchi

    PHYSIOLOGY & BEHAVIOR   61 ( 2 ) 165 - 168  1997.02

     View Summary

    To clarify the role of serotonin in penile erection, testosterone-primed castrated male rats were treated with the serotonin-synthesis inhibitor, p-chlorophenylalanine (pCPA), and reflexive erection (RE; male supine, penile sheath retracted) and noncontact erection (NCE; penile erection evoked by remote sexual stimuli) tests were performed. Half the males were injected with 100 mg/kg pCPA 4 times before each test; control males were treated with saline instead of pCPA. In the RE test, compared to the control group, pCPA-treated males had a shorter erection latency, but they also displayed fewer erections. NCE tests were conducted as a 2 x 2 factorial experiment: pCPA or saline, and estrous female present or absent. Only the pCPA-female Group had a high proportion of responders (68%), compared to 14-27% in the other Groups (p < 0.02). These results suggest that the serotonergic system exerts facilitative and inhibitory influences on different systems in regulating reflexive erection. On the other hand, serotonin appears to play an inhibitory role in the induction of noncontact erection, because pCPA did not directly induce erection, but rather facilitated the response to females. Copyright (C) 1997 Elsevier Science Inc.

    DOI

  • 性行動神経制御機構の性分化

    山内兄人

    アニテック   9( ( 2 ) 10 - 15  1997

  • Facilitatory effect of ventral cut of dorsal raphe nuclues on lordosis in female rats.

    Kakeyama,M, Negishi,M, Yamanouchi,K

    Endocrine J.   44 ( 4 ) 589 - 593  1997

    DOI PubMed CiNii

  • Facilitatory effect of ventral cut of dorsal raphe nuclues on lordosis in female rats.

    Kakeyama,M, Negishi,M, Yamanouchi,K

    Endocrine J.   44 ( 4 ) 589 - 593  1997

    DOI PubMed CiNii

  • Effects of p-chlorophenylalanine on male sexual behavior in female rats with mesencephalic raphe nuclei lesions

    Matsumoto,T.Yamanouchi, K

    Endocrine J.   44 ( 3 ) 383 - 388  1997

    DOI PubMed CiNii

  • Lordosis in male rats: Effect of dorsal raphe nucleus cuts

    Masaki Kakeyama, Korehito Yamanouchi

    Hormones and Behavior   32 ( 1 ) 60 - 67  1997

     View Summary

    The efferents and/or afferents of the dorsal raphe nucleus (DRN) were transected by several types of cut in castrated male rats, and lordosis behavior was observed after implantation with Silastic tubes containing estradiol. Throughout the behavioral tests, low incidences of lordosis were observed in control male rate without brain surgery or with a sham operation. In contrast, all male rats with a horizontal circle cut at the ventral area of the DRN displayed lordosis, and the mean lordosis quotient (LQ) was higher than that in control rats, while rats with a horizontal cut at the dorsal area of the DRN did not. Furthermore, mean LQs in male rats with an anterior half-circle horizontal cut at the ventral area of the DRN were higher than those in control groups. A posterior half-circle cut at the ventral area had no effect. In addition, male rats with a half-dome cut located anterior to the DRN showed a high LQ score, but rats with a posterior half-dome cut did not. These results suggest that anterior and anteroventral neural fibers of the DRN are involved in the lordosis inhibiting mechanism in male rats.

    DOI PubMed

  • Inhibitory effect of progesterone on sexual receptivity in female rats: A temporal relationship to estrogen administration

    M Satou, K Yamanouchi

    ZOOLOGICAL SCIENCE   13 ( 4 ) 609 - 613  1996.08

     View Summary

    The inhibitory effect of progesterone (P) injected at various times on female sexual behavior was investigated in estradiol benzoate (EB) treated ovariectomized rats. Four behavioral tests were carried out at two-week intervals. All females received 5 mu g/kg b.w. EB and 0.5 mg P 44 hr after the EB. In the P-control group, an additional 5 mg P was administered at the same time as the injection of EB in four tests. Instead of P, oil was given concurrently with EB in the Oil control group. In the experimental groups, female rats were treated with 5 mg P from 1 to 40 hr before (PB group) or after (PA group) the EB-injection. A sexual behavioral test was started 4 hr after 0.5 mg P. The results show that low levels of lordosis and soliciting behavior were observed in the P group, compared to the Oil-control group. In the PB groups, lordosis quotient (LQ) was low when P was given from 1 to 24 hr before EB. Moreover, animals in which P was given 27-40 hr before EB showed lower LQ than Oil-control animals, but higher LQ than rats in the P-control group. In the PA groups, when P was administered from 1 to 24 hr after EB, low levels of lordosis response were observed, whereas animals which received P 27-40 hr after EB showed a high score of LQ, being comparable to that in the Oil control. These results suggest that the period of 24 hr before and after EB injection is a critical period for inhibitory action of P on female sexual behavior in female rats.

  • Effects of chronic lesions in mesencephalic raphe nuclei on induction of pseudopregnancy

    F Maekawa, K Yamanouchi

    ENDOCRINE JOURNAL   43 ( 4 ) 369 - 374  1996.08

     View Summary

    The role of mesencephalic raphe nuclei in the induction of pseudopregnancy was investigated in female rats. The dorsal or median raphe nucleus lesions (DRL or MRL, respectively) were made by means of a radiofrequency lesion generator. Two or 3 weeks after the operation, in order to induce pseudopregnancy, the vagina was stimulated electrically on the day of proestrus or 1 mg/kg b.w. reserpine was injected on the day of diestrus I. Traumatization by passing thread to one uterine horn was performed to induce deciduoma 5 days after vaginal stimulation or 3 days after reserpine injection. As the results, decidual response was seen in most control and sham females in both vaginal stimulation and reserpine-treated groups. In contrast, incidences of deciduoma in DRL females with vaginal stimulation or reserpine-injection were significantly lower than those in control and sham groups. In the MRL females with either vaginal stimulation or reserpine-treatment, incidences of deciduoma were comparable to those of the control and sham operated groups. These results suggest that the dorsal raphe nucleus plays an important role in pseudopregnancy-inducing mechanisms in female rats.

    DOI PubMed CiNii

  • Inhibitory effect of baclofen on lordosis in female and male rats with dorsal raphe nucleus lesion or septal cut

    M Kakeyama, K Yamanouchi

    NEUROENDOCRINOLOGY   63 ( 3 ) 290 - 296  1996.03

     View Summary

    The inhibitory effect of baclofen, a GABA(B) receptor agonist, on lordosis was examined in female and male rats with dorsal raphe nucleus lesions (DRL) or cut of the septal fibers (ARD). Both female and male DRL and ARD rats showed higher lordosis quotients (LQ) than corresponding controls without brain surgery. This indicates that the dorsal raphe nucleus and the septum exert lordosis-inhibiting influences in female and male rats. After treatment with 10 mg/kg baclofen, the mean LQs in female control and female ARD groups were significantly lower than those of vehicle-treated control and ARD females. In DRL females, however, LQs did not decrease, even after the injection of baclofen. In males, baclofen also diminished lordosis in ARD rats, but not in DRL rats. These results suggest that the GABA(B) receptor system plays an inhibitory role in regulating lordosis behavior not only in female but also in male rats. Furthermore, the function of the GABA neurons depends on the inhibitory mechanism of the dorsal raphe nucleus in the regulation of female sexual behavior.

  • 性のメカニズム

    山内兄人

    ヒトと動物の関係学会誌   2 ( 1 ) 58 - 65  1996

  • 性行動の性分化:セロトニンニュ-ロン

    山内兄人, 鈴木香

    Brain Medical1996   8; ( 3 ) 257 - 263  1996

  • ラットの勃起-脊髄のメカニズム-

    山内兄人, 松本高広

    クリニカ   23 ( 2 ) 109 - 114  1996

  • 性行動における大脳皮質の役割

    山内兄人

    ヒュ-マンサイエンス   8 ( 2 ) 82 - 88  1996

  • Lordosis-inhibiting effect of progesterone in female rats with lesions in septum, preoptic area, or dorsal raphe nucleus

    Motoyasu Satou, Korehito Yamanouchi

    Physiology and Behavior   60 ( 3 ) 1027 - 1031  1996

     View Summary

    Radiofrequency lesions in the septum (SL), the preoptic area (POAL), or the dorsal raphe nucleus (DRL) were made in ovariectomized rats. In a control group of 16 females, ovariectomy, but no brain surgery, was performed. All animals except half of the control rats received injections of 5 mg progesterone (P) 1 h prior to the injection of 5 μg/kg b.w. of estradiol benzoate (EB). Instead of 5 mg P, oil was administered to half of the controls. Forty-four hours after EB, all females received 0.5 mg P. A sexual behavior test was performed 4 h after the last injection of P. The result was that oil-treated control rats showed high lordosis quotient (LQ) and soliciting behavior. in contrast, low scores of LQ and no soliciting behavior were observed in all of the 5 mg P-treated rats, even if the SL, POAL, or DRL was made. These results suggest that the septum, the preoptic area, and the dorsal raphe nucleus are not essential for the female sexual behavior-inhibiting mechanisms of progesterone.

    DOI PubMed

  • Effect of chronic lesions in mesencephalic raphe nuclei on induction of pseudopregnancy.

    Maekawa, F. Yamanouchi, K

    Endocrine. J.   43 ( 4 ) 369 - 374  1996

    DOI PubMed CiNii

  • Effects of deprivation of serotonin by p-chlorophenylalanine on induction and maintenance of pseudopregnancy in female rats

    Maekawa, F, Yamanouchi. K

    Brain Res.Bull.   39 ( 5 ) 317 - 321  1996

    DOI

  • Inhibitory effect of progesterone on sexual receptivity in female rats: A temporal relationship to estrogen administration.

    Satou, M, Yamanouchi, K

    Zool. Sci.   13 ( 4 ) 609 - 613  1996

  • Lordosis-inhibiting effect of progesterone in female rats with lesions in septum, preoptic area, or dorsal raphe nucleus

    Motoyasu Satou, Korehito Yamanouchi

    Physiology and Behavior   60 ( 3 ) 1027 - 1031  1996

     View Summary

    Radiofrequency lesions in the septum (SL), the preoptic area (POAL), or the dorsal raphe nucleus (DRL) were made in ovariectomized rats. In a control group of 16 females, ovariectomy, but no brain surgery, was performed. All animals except half of the control rats received injections of 5 mg progesterone (P) 1 h prior to the injection of 5 μg/kg b.w. of estradiol benzoate (EB). Instead of 5 mg P, oil was administered to half of the controls. Forty-four hours after EB, all females received 0.5 mg P. A sexual behavior test was performed 4 h after the last injection of P. The result was that oil-treated control rats showed high lordosis quotient (LQ) and soliciting behavior. in contrast, low scores of LQ and no soliciting behavior were observed in all of the 5 mg P-treated rats, even if the SL, POAL, or DRL was made. These results suggest that the septum, the preoptic area, and the dorsal raphe nucleus are not essential for the female sexual behavior-inhibiting mechanisms of progesterone.

    DOI PubMed

  • Effect of deprivation of serotonin by p-chlorophenylalanine on induction and maintenance of pseudopregnancy in female rats

    F Maekawa, K Yamanouchi

    BRAIN RESEARCH BULLETIN   39 ( 5 ) 317 - 321  1996

     View Summary

    The effect of serotonin synthesis inhibitor, p-chlorophenylalanine (PCPA), on induction and maintenance of pseudopregnancy as indicated by deciduoma formation was examined in female rats. Animals were injected with 1 mg/kg b.wt. of reserpine on the day of metestrus, and silk thread was passed through and placed in the left uterine horn 3 days after reserpine to induce deciduoma. PCPA (100 mg/kg b.wt.) was injected daily for 4 days before or after reserpine in 15 and 13 rats, respectively. A single injection of PCPA was administered before reserpine in nine females. In another group of rats (N = 16), instead of PCPA, saline was injected four times before reserpine. Nineteen female rats were treated with reserpine only as a control group. Results showed 89% of the control and 81.3% of the saline-treated females had massive deciduoma in traumatized uterine hem. In contrast, only 33.3% or 46.2% females with daily treatments of PCPA for 4 days before or after reserpine showed positive decidual reaction. In addition, 88.9% of females with single injection of PCPA possessed uterine hems with deciduoma. These results suggest that 4 days of treatment with PCPA eliminate induction and/or maintenance of pseudopregnancy. Thus, some levels of serotonin are required to induce and maintain pseudopregnancy.

    DOI

  • Inhibitory effect of baclofen on lordosis in female and male rats with dorsal raphe nucleus lesion or septal cut

    Masaki Kakeyama, Korehito Yamanouchi

    Neuroendocrinology   63 ( 3 ) 290 - 296  1996

     View Summary

    The inhibitory effect of baclofen, a GABAβ receptor agonist, on lordosis was examined in female and male rats with dorsal raphe nucleus lesions (DRL) or cut of the septal fibers (ARD). Both female and male DRL and ARD rats showed higher lordosis quotients (LQ) than corresponding controls without brain surgery. This indicates that the dorsal raphe nucleus and the septum exert lordosis-inhibiting influences in female and male rats. After treatment with 10 mg/kg baclofen, the mean LQs in female control and female ARD groups were significantly lower than those of vehicle-treated control and ARD females. In DRL females, however, LQs did not decrease, even after the injection of baclofen. In males, baclofen also diminished lordosis in ARD rats, but not in DRL rats. These results suggest that the GABAB receptor system plays an inhibitory role in regulating lordosis behavior not only in female but also in male rats. Furthermore, the function of the GABA neurons depends on the inhibitory mechanism of the dorsal raphe nucleus in the regulation of female sexual behavior. © 1996 S. Karger AG, Basel.

    DOI PubMed

  • 大脳皮質と男子性機能-ラットの実験結果から(

    山内兄人, 松本高広, 近藤保彦

    ホルモンと臨床   43 ( 2 ) 67 - 74  1995

  • THE POSSIBLE INVOLVEMENT OF THE NONSTRIAL PATHWAY OF THE AMYGDALA IN NEURAL CONTROL OF SEXUAL-BEHAVIOR IN MALE-RATS

    Y KONDO, K YAMANOUCHI

    BRAIN RESEARCH BULLETIN   38 ( 1 ) 37 - 40  1995

     View Summary

    The effect of medial amygdala lesions on male sexual behavior in male rats with stria terminalis cut was examined, First, castrated male rats received bilateral transections of the stria terminalis (STC) or sham cut (SC). Most STC males showed no ejaculation, but displayed mount and intromission, although the frequencies were not high compared to those of males with SC. Next, bilateral lesions of the medial amygdala (MAL) or sham lesion (SL) were performed in males with STC or SC. The MAL caused severe loss of all aspects of copulatory behavior in males with STC as well as in males with SC. The suppressive effect of the MAL on copulatory activity was stronger than that of the STC. These results indicate that a neural pathway other than the stria terminalis is involved in the regulation of male sexual behavior by the amygdala in male rats.

  • THE POSSIBLE INVOLVEMENT OF THE NONSTRIAL PATHWAY OF THE AMYGDALA IN NEURAL CONTROL OF SEXUAL-BEHAVIOR IN MALE-RATS

    Y KONDO, K YAMANOUCHI

    BRAIN RESEARCH BULLETIN   38 ( 1 ) 37 - 40  1995

     View Summary

    The effect of medial amygdala lesions on male sexual behavior in male rats with stria terminalis cut was examined, First, castrated male rats received bilateral transections of the stria terminalis (STC) or sham cut (SC). Most STC males showed no ejaculation, but displayed mount and intromission, although the frequencies were not high compared to those of males with SC. Next, bilateral lesions of the medial amygdala (MAL) or sham lesion (SL) were performed in males with STC or SC. The MAL caused severe loss of all aspects of copulatory behavior in males with STC as well as in males with SC. The suppressive effect of the MAL on copulatory activity was stronger than that of the STC. These results indicate that a neural pathway other than the stria terminalis is involved in the regulation of male sexual behavior by the amygdala in male rats.

  • 縫線核と生殖機能

    掛山正心, 山内兄人

    ヒューマンサイエンス   7 ( 1 ) 78 - 91  1994

  • 神経制御機構における性分化-中隔と背側縫線核のロードーシス抑制力(共著)

    性差医学シンポジウム   2   52 - 65  1994

  • 性と生殖:ラットとヒトを比べてみれば(単著)

    ヒューマンサイエンス   6/2,89-102  1994

  • 性行動神経制御機構とモノアミンニューロン(単著)

    脳と精神の医学   5/4,387-399  1994

  • Two types of Lordosis inhibiting system in male rats : Dorsal raphe nucleus lesions and septal cuts

    Kakeyama, M, Yamanouchi, K

    Physiol. Behav.   56 ( 1 ) 189 - 192  1994

  • 性行動とホルモン:脳内におけるアンドロゲン情報と嗅覚情報の接点(共著)

    近藤保彦, 山内兄人

    クリニカルニューロサイエンス   11 ( 4 ) 407 - 410  1993

  • p-chlorophenylalanine facilitates copulatory behavior in septal lesioned but not in preoptic lesioned male rats(共著)

    Kondo, Y, Yamanouchi, K, Arai, Y

    J. Neuroendocrinology   5 ( 6 ) 629 - 633  1993

    DOI PubMed CiNii

  • FUNCTIONAL-RELATIONSHIPS BETWEEN MESENCEPHALIC CENTRAL GRAY AND SEPTUM IN REGULATING LORDOSIS IN FEMALE RATS - EFFECT OF DUAL LESIONS

    Y KONDO, T KOIZUMI, Y ARAI, M KAKEYAMA, K YAMANOUCHI

    BRAIN RESEARCH BULLETIN   32 ( 6 ) 635 - 638  1993

     View Summary

    In order to clarify the functional relationships between the lateral septum (LS) and the mesencephalic central gray (MCG) in regulating lordosis behavior, ovariectomized female rats received dual lesions in these two areas. In the first experiment, females with unilateral (right or left, R-MCGL or L-MCGL) or bilateral MCG (B-MCG) lesions were subjected to behavioral tests after the implantation of a Silastic tube containing estradiol. Lordosis was observed in only one B-MCGL female. In the R-MCGL and L-MCGL groups, most females displayed lordosis, but lordosis quotients (LQ) were significantly lower than that of the control group. These results suggest the importance of the MCG in lordosis regulation, and that there is no functional laterality in the MCG. In the second experiment, B-MCGL or R-MCGL females received bilateral LS lesions (LSL). The lordotic activity in the LSL + B-MCGL group was extremely low, being comparable to that of B-MCGL alone. On the other hand, in the LSL + R-MCGL females, the LQ was significantly higher than that of females with R-MCGL alone and was comparable to that of controls. Thus. the lateral septum plays an inhibitory role in regulating lordosis, but the influence of the lateral septum is not stronger than the facilitatory influence of the mesencephalic central gray, because the LSL could not recover the suppressive effect of the MCGL.

  • FEMALE SEXUAL BEHAVIORS IN MALE-RATS WITH DORSAL RAPHE NUCLEUS LESIONS - TREATMENT WITH P-CHLOROPHENYLALANINE

    M KAKEYAMA, K YAMANOUCHI

    BRAIN RESEARCH BULLETIN   30 ( 5-6 ) 705 - 709  1993

    Article, review, commentary, editorial, etc. (scientific journal)  

     View Summary

    The effects of the serotonin-synthesis inhibitor, p-chlorophenylalanine (PCPA) on female sexual behaviors were examined in male rats with or without lesions (DRL) of the dorsal raphe nucleus, which contains a large number of serotonergic cell bodies. Estrogen-primed castrated males without brain surgery (control) showed extremely low levels of lordosis compared with females. On the other hand, DRL males displayed lordosis response more frequently than control males, but the lordosis quotient (LQ) in this group was lower than that in females. As well as DRL males, all PCPA-treated males showed lordosis, the mean LQ being comparable to the DRL group. Thus, the destruction of the dorsal raphe nucleus or the deprivation of serotonin by PCPA treatment facilitates manifestation of lordosis behavior in male rats. However, synergistic effect of DRL and PCPA treatments on female sexual behaviors have not been observed. The mean LQ in PCPA-treated male rats with DRL was almost the same as in DRL males or PCPA-treated males. These results suggest that the possible site of action of PCPA in regulating female sexual behavior in male rats is the serotonergic neurons in the dorsal raphe nucleus. Furthermore, the lordosis-facilitating effect of DRL is due to destruction of the serotonergic cell bodies in the dorsal raphe nucleus.

  • p-chlorophenylalanine facilitates copulatory behavior in septal lesioned but not in preoptic lesioned male rats(共著)

    Kondo, Y, Yamanouchi, K, Arai, Y

    J. Neuroendocrinology   5 ( 6 ) 629 - 633  1993

    DOI PubMed CiNii

  • FUNCTIONAL-RELATIONSHIPS BETWEEN MESENCEPHALIC CENTRAL GRAY AND SEPTUM IN REGULATING LORDOSIS IN FEMALE RATS - EFFECT OF DUAL LESIONS

    Y KONDO, T KOIZUMI, Y ARAI, M KAKEYAMA, K YAMANOUCHI

    BRAIN RESEARCH BULLETIN   32 ( 6 ) 635 - 638  1993

     View Summary

    In order to clarify the functional relationships between the lateral septum (LS) and the mesencephalic central gray (MCG) in regulating lordosis behavior, ovariectomized female rats received dual lesions in these two areas. In the first experiment, females with unilateral (right or left, R-MCGL or L-MCGL) or bilateral MCG (B-MCG) lesions were subjected to behavioral tests after the implantation of a Silastic tube containing estradiol. Lordosis was observed in only one B-MCGL female. In the R-MCGL and L-MCGL groups, most females displayed lordosis, but lordosis quotients (LQ) were significantly lower than that of the control group. These results suggest the importance of the MCG in lordosis regulation, and that there is no functional laterality in the MCG. In the second experiment, B-MCGL or R-MCGL females received bilateral LS lesions (LSL). The lordotic activity in the LSL + B-MCGL group was extremely low, being comparable to that of B-MCGL alone. On the other hand, in the LSL + R-MCGL females, the LQ was significantly higher than that of females with R-MCGL alone and was comparable to that of controls. Thus. the lateral septum plays an inhibitory role in regulating lordosis, but the influence of the lateral septum is not stronger than the facilitatory influence of the mesencephalic central gray, because the LSL could not recover the suppressive effect of the MCGL.

  • 雄性行動神経制御における嗅覚系の重要性(共著)

    近藤保彦, 山内兄人

    ヒューマンサイエンス   5 ( 1 ) 2 - 16  1992

  • Effects of unilateral hypothalamic lesion on serum gonadotropin in hemiovariectomized rats. (共著)

    Fukuda,M, Hashimoto R, Yamanouchi, K, Arai, Y, Kimura, f, Takada, M

    Zool. Sci.   9 ( 1 ) 223 - 226  1992

  • Possible role of cingulate cortex in regulating sexual behavior in male rats : Effects of lesions and cuts.(共著)

    Yamanouchi, K. Arai, Y

    Endocrinol. Japon.   39 ( 3 ) 229 - 234  1992

    DOI PubMed CiNii

  • Lordosis in male rats : The facilitatory effect of mesencephalic dorsal raphe nucleus lesion. (共著)

    Kakayama, M, Yamanouchi, K

    Physiol. Behav.   51 ( 3 ) 575 - 579  1992

  • Effect of medullary raphe lesions on sexual behavior in male rats with or without treatments of p-chlorophenylalanine.(共著)

    Yamanouchi, K, Kakeyama, M

    Physiol. Behav.   51 ( 3 ) 575 - 579  1992

  • Effects of unilateral hypothalamic lesion on serum gonadotropin in hemiovariectomized rats. (共著)

    Fukuda,M, Hashimoto R, Yamanouchi, K, Arai, Y, Kimura, f, Takada, M

    Zool. Sci.   9 ( 1 ) 223 - 226  1992

  • Possible role of cingulate cortex in regulating sexual behavior in male rats : Effects of lesions and cuts.(共著)

    Yamanouchi, K. Arai, Y

    Endocrinol. Japon.   39 ( 3 ) 229 - 234  1992

    DOI PubMed CiNii

  • Lordosis in male rats : The facilitatory effect of mesencephalic dorsal raphe nucleus lesion. (共著)

    Kakayama, M, Yamanouchi, K

    Physiol. Behav.   51 ( 3 ) 575 - 579  1992

  • Effect of medullary raphe lesions on sexual behavior in male rats with or without treatments of p-chlorophenylalanine.(共著)

    Yamanouchi, K, Kakeyama, M

    Physiol. Behav.   51 ( 3 ) 575 - 579  1992

  • ROLE OF THE MEDULLARY RAPHE NUCLEUS IN REGULATING SEXUAL BEHAVIORS IN FEMALE RATS

    K YAMANOUCHI

    ZOOLOGICAL SCIENCE   7 ( 5 ) 907 - 912  1990.10

  • 幼若雄および幼若雄性化雌ラットにおける母性行動(共著)

    山内兄人, 鈴木陽子

    ヒューマンサイエンス   3 ( 2 ) 53 - 56  1990

  • Role of septum and preoptic area in regulating masculine and feminine sexual behavior in male rats. (共著)

    Kondo, Y, Shinoda, A, Yamanouchi, K, Arai, Y

    Horm. Behav.   24 ( 3 ) 421 - 434  1990

  • The septum as origin of a lordosis inhibiting influence in female rats : Effect of neural transection(共著)

    Yamanouchi, K, Arai, Y

    Physiol, Behav. ,   48 ( 2 ) 351 - 355  1990

  • Roles of the pontine dorsomedial tegmentum and midbrain central gray in regulating female rat sexual behaviors : Effects of p-chlorophenylalanine. (共著)

    Yamanouchi, K. Nakano, Y, Arai, Y

    Brain Res. Bull.   25 ( 3 ) 381 - 386  1990

  • Role of septum and preoptic area in regulating masculine and feminine sexual behavior in male rats. (共著)

    Kondo, Y, Shinoda, A, Yamanouchi, K, Arai, Y

    Horm. Behav.   24 ( 3 ) 421 - 434  1990

  • Role of the medullary raphe nucleus in regulating sexual behaviors in female rats.

    Yamanouhci, K

    Zool. Sci. ,   7 ( 5 ) 907 - 912  1990

  • The septum as origin of a lordosis inhibiting influence in female rats : Effect of neural transection(共著)

    Yamanouchi, K, Arai, Y

    Physiol, Behav. ,   48 ( 2 ) 351 - 355  1990

  • Roles of the pontine dorsomedial tegmentum and midbrain central gray in regulating female rat sexual behaviors : Effects of p-chlorophenylalanine. (共著)

    Yamanouchi, K. Nakano, Y, Arai, Y

    Brain Res. Bull.   25 ( 3 ) 381 - 386  1990

  • ロード-シス神経制御機構:セロトニンニューロン(共著)

    ヒューマンサイエンス   2/2,70-80  1989

  • Lordosis-inhibiting pathway in the lateral hypothalamus : Medial forebrain bundle(MFB)transaction.(共著)

    Yamanouchi, K, Arai, Y

    Zool. Sci. ,   6 ( 1 ) 141 - 145  1989

  • Induction of male sexual behaviors by administration of testosterone using silastic tubes in castrated male and female rats. (共著)

    Kusaka, S, Nagasawa, H, Yamanouchi, K, Arai, Y

    Zool. Sci. ,   6 ( 5 ) 1037 - 1040  1989

  • Lordosis-inhibiting pathway in the lateral hypothalamus : Medial forebrain bundle(MFB)transaction.(共著)

    Yamanouchi, K, Arai, Y

    Zool. Sci. ,   6 ( 1 ) 141 - 145  1989

  • Induction of male sexual behaviors by administration of testosterone using silastic tubes in castrated male and female rats. (共著)

    Kusaka, S, Nagasawa, H, Yamanouchi, K, Arai, Y

    Zool. Sci. ,   6 ( 5 ) 1037 - 1040  1989

  • Neural transection between preoptic area and septum inhibits maternal behavior in female and male rats.(共著)

    Koranyi, L, Yamanouchi, K. Arai, Y

    Neurosci. Res. ,   6 ( 2 ) 167 - 173  1988

  • Neural transection between preoptic area and septum inhibits maternal behavior in female and male rats.(共著)

    Koranyi, L, Yamanouchi, K. Arai, Y

    Neurosci. Res. ,   6 ( 2 ) 167 - 173  1988

  • 実験動物と向精神薬-III-下垂体ホルモン分泌への影響(共著)

    山内兄人, 齋藤伸, 金哲, 新井康允

    ラボラトリーアニマル   4 ( 1 ) 50 - 55  1987

  • Suppressive effect of right-side anterior hypothalamic lesion on ovarian compensatory hypertrophy in rats.(共著)

    Fukuda, M, Nakano, Y, Yamanouchi, K, Arai, Y, Furuya, H

    Zool. Sci. ,   4 ( 1 ) 197 - 199  1987

  • Suppressive effect of right-side anterior hypothalamic lesion on ovarian compensatory hypertrophy in rats.(共著)

    Fukuda, M, Nakano, Y, Yamanouchi, K, Arai, Y, Furuya, H

    Zool. Sci. ,   4 ( 1 ) 197 - 199  1987

  • 実験動物と向精神薬-Ⅱー行動の変化

    斎藤伸, 金哲, 山内兄人, 新井康允

    ラボラトリーアニマル   3 ( 6 ) 47 - 52  1986

  • 実験動物と向精神薬-Ⅱー向精神薬の種類と作用機序

    金哲, 斎藤伸, 山内兄人, 新井康允

    ラボラトリーアニマル   3 ( 5 ) 46 - 50  1986

  • Perinatal androgen exposure decreases the size of the sexually dimorphic medial preoptic nucleus in the rat. (共著)

    Ito,S, Murakami, S, Yamanouchi, K, Arai,Y

    Proc. Japan Acad.   62 ( 10 ) 408 - 411  1986

    DOI CiNii

  • Recovery of lordotic activity by dorsal deafferentation of the preoptic area in male and androgenized female rats. (共著)

    Kondo, Y, shinoda, A, Yamanouchi, K, Arai, Y

    Physiol. Behav. ,   37 ( 3 ) 495 - 498  1986

  • Perinatal androgen exposure decreases the size of the sexually dimorphic medial preoptic nucleus in the rat. (共著)

    Ito,S, Murakami, S, Yamanouchi, K, Arai,Y

    Proc. Japan Acad.   62 ( 10 ) 408 - 411  1986

    DOI CiNii

  • Recovery of lordotic activity by dorsal deafferentation of the preoptic area in male and androgenized female rats. (共著)

    Kondo, Y, shinoda, A, Yamanouchi, K, Arai, Y

    Physiol. Behav. ,   37 ( 3 ) 495 - 498  1986

  • 母性行動はどうしておこるのか?‐雄も母性行動を示す

    Koranyi L, 山内兄人

    ラボラトリーアニマル   2 ( 6 ) 26 - 31  1985

  • Neural and hormonal control of lordosis behavior in the rat. (共著)

    Yamanouchi, K, Matusmoto A, Arai, Y

    Zool. Sci.   2 ( 5 ) 617 - 627  1985

  • The role of mesencephalic tegmentum in regulating female rat sexual behaviors. (共著)

    Yamanouchi, K, Arai, Y

    Physiol. Behav.   35 ( 2 ) 255 - 259  1985

  • Presence of a neural mechanism for the expression of female sexual behavior in the male rat brain.(共著)

    Yamanouhci, K, Arai, Y

    Neuroendocrinol.   40/5,393-397 ( 5 ) 393 - 397  1985

  • Neural and hormonal control of lordosis behavior in the rat. (共著)

    Yamanouchi, K, Matusmoto A, Arai, Y

    Zool. Sci.   2 ( 5 ) 617 - 627  1985

  • The role of mesencephalic tegmentum in regulating female rat sexual behaviors. (共著)

    Yamanouchi, K, Arai, Y

    Physiol. Behav.   35 ( 2 ) 255 - 259  1985

  • Presence of a neural mechanism for the expression of female sexual behavior in the male rat brain.(共著)

    Yamanouhci, K, Arai, Y

    Neuroendocrinol.   40/5,393-397 ( 5 ) 393 - 397  1985

  • 性行動:ホルモンによる誘起

    山内兄人

    ラボラトリーアニマル   1 ( 3 ) 11 - 17  1984

  • Hypothalamic laterality in regulating gonadotropic function : Unilateral hypothalamic lesion and ovarian compensatory hypertrophy.(共著)

    Fukuda,M, Yamanouchi, K. Nakano, Y. Furuya, H, Arai, Y

    Neurosci. Lett. ,   51 ( 3 ) 365 - 370  1984

  • Mesencephalic central gray as supraspinal neural substrates for lordosis reflex : Deprivasion of serotonergic influence by p-chlorophenylalanine. (共著)

    Yamanouchi, K, Nakano, Y, Fukuda, M, Arai, Y

    Zool. Sci. ,   1 ( 3 ) 126 - 131  1984

  • Hypothalamic laterality in regulating gonadotropic function : Unilateral hypothalamic lesion and ovarian compensatory hypertrophy.(共著)

    Fukuda,M, Yamanouchi, K. Nakano, Y. Furuya, H, Arai, Y

    Neurosci. Lett. ,   51 ( 3 ) 365 - 370  1984

  • Mesencephalic central gray as supraspinal neural substrates for lordosis reflex : Deprivasion of serotonergic influence by p-chlorophenylalanine. (共著)

    Yamanouchi, K, Nakano, Y, Fukuda, M, Arai, Y

    Zool. Sci. ,   1 ( 3 ) 126 - 131  1984

  • 哺乳類の発情―雌ラットの実験から

    山内兄人

    動物と自然   13 ( 6 ) 14 - 21  1983

  • FOREBRAIN AND LOWER BRAIN-STEM PARTICIPATION IN FACILITATORY AND INHIBITORY REGULATION OF THE DISPLAY OF LORDOSIS IN FEMALE RATS

    K YAMANOUCHI, Y ARAI

    PHYSIOLOGY & BEHAVIOR   30 ( 1 ) 155 - 159  1983

    Article, review, commentary, editorial, etc. (scientific journal)  

  • FOREBRAIN AND LOWER BRAIN-STEM PARTICIPATION IN FACILITATORY AND INHIBITORY REGULATION OF THE DISPLAY OF LORDOSIS IN FEMALE RATS

    K YAMANOUCHI, Y ARAI

    PHYSIOLOGY & BEHAVIOR   30 ( 1 ) 155 - 159  1983

    Article, review, commentary, editorial, etc. (scientific journal)  

  • FAILURE OF OVULATION AFTER NEONATAL ADMINISTRATION OF 5-ALPHA-DIHYDROTESTOSTERONE TO FEMALE RATS

    S MIZUKAMI, K YAMANOUCHI, Y ARAI, R YANAI, H NAGASAWA

    ENDOKRINOLOGIE   79 ( 1 ) 1 - 6  1982

  • Forebrain lordosis inhibiting system and serotonin neuron in female rats : Effect of p-chloroamphetamine.(共著)

    Yamanouhci,K, Watanabe, H, Okada, R, Arai, Y

    Endocrinol. Japon.   29 ( 4 ) 469 - 474  1982

    DOI PubMed CiNii

  • Dissociation between the display of lordosis and soliciting behaviors in female rats with lesions of the dorsomedial pontine tegmentum. (共著)

    Yamanouchi, K, Arai, Y

    Physiol. Behav. ,   28 ( 1 ) 155 - 159  1982

  • FAILURE OF OVULATION AFTER NEONATAL ADMINISTRATION OF 5-ALPHA-DIHYDROTESTOSTERONE TO FEMALE RATS

    S MIZUKAMI, K YAMANOUCHI, Y ARAI, R YANAI, H NAGASAWA

    ENDOKRINOLOGIE   79 ( 1 ) 1 - 6  1982

  • Forebrain lordosis inhibiting system and serotonin neuron in female rats : Effect of p-chloroamphetamine.(共著)

    Yamanouhci,K, Watanabe, H, Okada, R, Arai, Y

    Endocrinol. Japon.   29 ( 4 ) 469 - 474  1982

    DOI PubMed CiNii

  • Dissociation between the display of lordosis and soliciting behaviors in female rats with lesions of the dorsomedial pontine tegmentum. (共著)

    Yamanouchi, K, Arai, Y

    Physiol. Behav. ,   28 ( 1 ) 155 - 159  1982

  • 生理活性アミンと生殖行動

    新井康允, 山内兄人

    蛋白核酸酵素(臨時増刊)   26 ( 11 ) 1741 - 1745  1981

  • Induction of anovulatory sterility by neonatal treatment with 5β-dihydrotestosterone in female rats.

    Arai, Y, Yamanouchi, K, Mizukami, S, Yanai, R. Shibata K, Nagasawa, H

    Acta Endocrinol. ,   96 ( 3 ) 439 - 443  1981

  • Induction of anovulatory sterility by neonatal treatment with 5β-dihydrotestosterone in female rats.

    Arai, Y, Yamanouchi, K, Mizukami, S, Yanai, R. Shibata K, Nagasawa, H

    Acta Endocrinol. ,   96 ( 3 ) 439 - 443  1981

  • INTERRUPTION OF PSEUDOPREGNANCY BY ROSTRAL PERIVENTRICULAR PREOPTIC LESIONS IN THE FEMALE RAT

    H WATANABE, H FURUYA, R OKADA, K YAMANOUCHI, Y ARAI

    ENDOKRINOLOGIE   76 ( 2 ) 181 - 184  1980

    Article, review, commentary, editorial, etc. (scientific journal)  

  • Recovery of sexual receptivity in female rats with lesions of the ventromedial hypothalamus.(共著)

    Okada, r, Watanabe, H, Yamanouchi, K, Arai, Y

    Exp. Neurol. ,   68 ( 3 ) 595 - 600  1980

  • Mounting and lordosis behavior in androgen primed ovariectomized rats : Effect of dorsal deafferentation of the preoptic area and hypothalamus.

    Yamanouchi, K

    Endocrinol. Japon.   27 ( 4 ) 499 - 504  1980

    DOI CiNii

  • INHIBITORY AND FACILITATORY NEURAL MECHANISMS INVOLVED IN THE REGULATION OF LORDOSIS BEHAVIOR IN FEMALE RATS - EFFECTS OF DUAL CUTS IN THE PREOPTIC AREA AND HYPOTHALAMUS

    K YAMANOUCHI

    PHYSIOLOGY & BEHAVIOR   25 ( 5 ) 721 - 725  1980

  • INTERRUPTION OF PSEUDOPREGNANCY BY ROSTRAL PERIVENTRICULAR PREOPTIC LESIONS IN THE FEMALE RAT

    H WATANABE, H FURUYA, R OKADA, K YAMANOUCHI, Y ARAI

    ENDOKRINOLOGIE   76 ( 2 ) 181 - 184  1980

    Article, review, commentary, editorial, etc. (scientific journal)  

  • Recovery of sexual receptivity in female rats with lesions of the ventromedial hypothalamus.(共著)

    Okada, r, Watanabe, H, Yamanouchi, K, Arai, Y

    Exp. Neurol. ,   68 ( 3 ) 595 - 600  1980

  • Mounting and lordosis behavior in androgen primed ovariectomized rats : Effect of dorsal deafferentation of the preoptic area and hypothalamus.

    Yamanouchi, K

    Endocrinol. Japon.   27 ( 4 ) 499 - 504  1980

    DOI CiNii

  • Inhibitory and facilitatory neural mechanisms involved in the regulation of lordosis behavior in female rats : Effects of dual cuts in the preoptic area and hypothalamus.

    Yamanouchi, K

    Physiol Behav. ,   25 ( 5 ) 721 - 725  1980

  • 発情・求愛・性欲―性行動の神経内分泌制御

    山内兄人, 西塚雅子

    代謝(臨時増刊―性Ⅱ)   15   1375 - 1382  1979

  • Effects of hypothalamic deafferentation on hormonal facilitation of lordosis in ovariectomized rats. (共著)

    Yamanouchi, K, Arai, Y

    Endocrinol. Japon. ,   26 ( 3 ) 307 - 312  1979

    DOI PubMed CiNii

  • Effects of hypothalamic deafferentation on hormonal facilitation of lordosis in ovariectomized rats. (共著)

    Yamanouchi, K, Arai, Y

    Endocrinol. Japon. ,   26 ( 3 ) 307 - 312  1979

    DOI PubMed CiNii

  • Lordosis behaviour in male rats ; Effect of deafferentation in the preoptic area and hypothalamus.

    Yamanouchi, K, Arai, Y

    J. Endocrinol. ,   76 ( 2 ) 381 - 382  1978

  • Lordosis behaviour in male rats ; Effect of deafferentation in the preoptic area and hypothalamus.

    Yamanouchi, K, Arai, Y

    J. Endocrinol. ,   76 ( 2 ) 381 - 382  1978

  • Possible Inhibitory role of the dorsal inpouts to the preoptic area and hypothalamus in regulating female sexual behavior in the female rat.(共著)

    Yamanouchi, K, Arai, Y

    Brain Res. ,   127 ( 2 ) 296 - 301  1977

  • Possible Inhibitory role of the dorsal inpouts to the preoptic area and hypothalamus in regulating female sexual behavior in the female rat.(共著)

    Yamanouchi, K, Arai, Y

    Brain Res. ,   127 ( 2 ) 296 - 301  1977

  • Inhibition of pituitary prolactin secretion by human placental lactogen in rats

    Nagasawa, H, Yanai,R, Yamanouchi, K

    J. Endocrinol. ,   71 ( 1 ) 115 - 120  1976

  • Heterotypical sexual behavior in male rats : Individual difference in lordosis response. (共著)

    Yamanouchi, K. Arai, Y

    Endocrinol. Japon. ,   23 ( 2 ) 179 - 182  1976

  • Inhibition of pituitary prolactin secretion by human placental lactogen in rats

    Nagasawa, H, Yanai,R, Yamanouchi, K

    J. Endocrinol. ,   71 ( 1 ) 115 - 120  1976

  • Heterotypical sexual behavior in male rats : Individual difference in lordosis response. (共著)

    Yamanouchi, K. Arai, Y

    Endocrinol. Japon. ,   23 ( 2 ) 179 - 182  1976

  • Possible role of anterior inputs to the medial basal hypothalamus(MBH)in regulating prolactin release during pseudopregnancy in the rat.(共著)

    Arai, Y, Yamanouchi, K

    Brain Res. ,   83 ( 1 ) 51 - 58  1975

  • Female lordosis pattern in the male rat induced by estrogen and progesterone : Effect of interruption of the dorsal inputs to the preoptic area hypothalamus

    Yamanouchi, K. Arai, Y

    Endocrinol. Japon. ,   22 ( 3 ) 243 - 246  1975

  • Possible role of anterior inputs to the medial basal hypothalamus(MBH)in regulating prolactin release during pseudopregnancy in the rat.(共著)

    Arai, Y, Yamanouchi, K

    Brain Res. ,   83 ( 1 ) 51 - 58  1975

  • Female lordosis pattern in the male rat induced by estrogen and progesterone : Effect of interruption of the dorsal inputs to the preoptic area hypothalamus

    Yamanouchi, K. Arai, Y

    Endocrinol. Japon. ,   22 ( 3 ) 243 - 246  1975

  • Effect of perinatal hypothyroidism on pituitary secretion of growth hormone and prolactin in rats

    Kikuyama, S, Nagasawa, H, Yanai, R, Yamanouchi, K

    J. Endocrinol. ,   62 ( 2 ) 213 - 223  1974

  • Effect of hypothalamic deafferentation of reserpine induced lactogenesis in female rats (共著)

    Yamanouchi, K. Arai, Y

    Annot. Zool. Japon.   47 ( 3 ) 133 - 139  1974

  • Effect of perinatal hypothyroidism on pituitary secretion of growth hormone and prolactin in rats

    Kikuyama, S, Nagasawa, H, Yanai, R, Yamanouchi, K

    J. Endocrinol. ,   62 ( 2 ) 213 - 223  1974

  • Effect of hypothalamic deafferentation of reserpine induced lactogenesis in female rats (共著)

    Yamanouchi, K. Arai, Y

    Annot. Zool. Japon.   47 ( 3 ) 133 - 139  1974

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Research Projects

  • 植物含有エストロゲン様物質の作用

  • 脳の左右差

  • 脳の性差

  • 生殖機能の神経制御機構

  • 中枢神経系における性殖行動制御

  • 中枢神経系の性分化

  • 中枢神経系における生殖制御機構

  • Regulatory mechanisms for sexual behavior in the central nervous system

  • Sexual differentiation of the central nervous system

  • Regulatory mechanisms of reproduction in the central nervous system

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Presentations

  • 視床下部腹内側核左側破壊による右側エストロゲンα受容体免疫陽性細胞数の変化、

    動物学会第81回大会 

    Presentation date: 2012

  • 視床下部腹内側部片側破壊による反対側におけるエストロゲン受容体α免疫陽性細胞数の増加

    第39回日本神経内分泌学会 

    Presentation date: 2012

  • 雄ラットのロードーシス発現に対する新生期中隔破壊効果動

    動物学会第83回大会 

    Presentation date: 2012

  • 卵巣除去ラット視床下部腹内側片側破壊による反対側ERα免疫陽性細胞数、mRNA量の増加

    動物学会第83回大会 

    Presentation date: 2012

  • 第35回日本神経科学会大会 

    Presentation date: 2012

  • 第35回日本神経科学会大会 

    Presentation date: 2012

  • Neonatal septal lesions prevent behavior defeminization but not anovulatory syndome by neonatal-treatment with estrogen in female rats

    Presentation date: 2012

  • Effects of medial prefrontal cortex lesion on anovulatory syndrome by over exercise and adrenal secretions in female rats

    Presentation date: 2012

  • Involvement of the septum on neonatal estrogen-induced behavioral defeminization in rats

    42th Annual meeting of Sosiety for Neuroscience, Neorleans 

    Presentation date: 2012

  • ロードーシス行動抑制力と40年

    日本行動神経内分泌研究会、鋤鼻研究会合同集会 

    Presentation date: 2011

  • 雌ラットの脳機能の雄性化に対するエストロゲンα、β受容体作動剤新生期投与効果

    第16回日本生殖内分泌学会 

    Presentation date: 2011

  • 雌ラット視床下部ERα免疫陽性細胞数へのERα、β作動剤、性ステロイド投与効果

    動物学会第82回大会 

    Presentation date: 2011

  • 第34回日本神経科学会大会、 

    Presentation date: 2011

  • Increase of estrogen receptor α-immunoreactive cells in intact side of ventromedial hypothalamic nucleus by unilateral lesion.

    Presentation date: 2011

  • Shimogawa Y. and Yamanouchi K

    The 8th World Congress of Neuroscience, 

    Presentation date: 2011

  • Effects of unilateral lesion of ventromedial hypothalamus on densities of estrogen redceptor α-immunoreactive cells in intact side. The 8th World Congress of Neuroscience,

    The 8th World Congress of Neuroscience 

    Presentation date: 2011

  • セロトニン神経と生殖機能

    シンポジウム「応用脳科学研究の展開」 

    Presentation date: 2010

  • ロードーシス行動と性差

    ラットリソースリサーチ研究会 

    Presentation date: 2010

  • 第33回日本神経科学会大会、9月2-4日、2010、神戸 

    Presentation date: 2010

  • 雌ラット子宮に対する植物エストロゲンおよびエストロゲン受容体作動剤の影響

    動物学会第81回大会 

    Presentation date: 2010

  • 雌ラット発情周期とロードーシスに対するエストロゲン受容体α、β作動剤新生期投与

    動物学会第81回大会 

    Presentation date: 2010

  • 雌ラット運動負荷による性周期異常に対する中脳縫線核,前頭前野皮質の役割:破壊効果

    動物学会第81回大会 

    Presentation date: 2010

  • Effects of serotonin-synthesis inhibitor, parachlorophenylalanine, on number of estrogen receptor alpha immunoreactive cells in gonadectomized female and male rats.

    The 7th International Congress of Neuroendocrinology,July 11-15, 2010 

    Presentation date: 2010

  • Defeminizing and masculinizing effects of single injection with estrogen receptor alpha or beta agonist in neonatal female rats. The 7th International Congress of Neuroendocrinology

    International Congress of Neuroendocrinology, July 11-15, 2010 

    Presentation date: 2010

  • Effects of single injection of phytoestrogens or estrogen receptor alpha and beta agonists on uteri in ovariectomized rats.

    International Congress of Neuroendocrinology, July 11-15, 2010 

    Presentation date: 2010

  • Effects of neonatally-treatment with ER alpha and ER beta agonists on estrous cycle and lordosis in female rats

    Presentation date: 2010

  • セロトニン合成阻害剤投与ラットにおける縫線核セロトニン免疫陽性細胞数の性差

    動物学会第80回大会 

    Presentation date: 2009

  • 運動負荷による無排卵症に対するラット縫線核破壊による促進効果

    第32回日本神経科学大会 

    Presentation date: 2009

  • 縫線核セロトニン免疫陽性細胞数に対するp-chlorophenylalanin投与効果の性差

    第32回日本神経科学大会 

    Presentation date: 2009

  • 動物の本能行動から脳の性差を考える

    2009年日仏春秋講座「男の脳・女の脳―脳に性差はあるのか」 

    Presentation date: 2009

  • 脳機能の性分化:性行動と母性行動

    第161回つくばブレインサイエンス・セミナー 

    Presentation date: 2009

  • ラット雄間攻撃行動に対する中隔とアンドロゲンの役割

    動物学会関東支部第61回大会 

    Presentation date: 2009

  • Sex difference of p-chlorophenylalanine-sensitivity in serotonin-immunoreactive cells in rat raphe nuclei

    16th Int. Cong. of Comparative Endocrinology, Hong-Kong 

    Presentation date: 2009

  • Effect of mesencephalic raphe nuclei lesions on anovulation caused by over exercise stress in female rats,

    16th International Congress of Comparative Endocrinology 

    Presentation date: 2009

  • ラット前脳に対する中脳縫線核セロトニン神経投射の左右差:二重蛍光免疫染色による投射細胞数の解析

    第31回日本神経科学大会 

    Presentation date: 2008

  • 植物エストロゲン、クメステロールによる視床下部エストロゲンα受容体免疫陽性細胞数の減少

    第35回日本神経内分泌学会 

    Presentation date: 2008

  • 雌ラット視床下部におけるエストロゲンα受容体に対する植物エストロゲン投与効果

    第79回日本動物学会大会 

    Presentation date: 2008

  • 雄ラット中脳縫線核におけるセロトニン免疫陽性細胞数の出生後変化

    第79回日本動物学会大会 

    Presentation date: 2008

  • 雌ラットの中隔破壊が脳内エストロジェン受容体α発現に及ぼす影響

    第101回日本繁殖生物学会大会 

    Presentation date: 2008

  • Effect of lateral septum lesions on expression of estrogen receptor α in the rat brain

    US/Japan neurosteroid symposium 

    Presentation date: 2008

  • Sex and regional differences in number of estrogen receptor α immunoreactive cells in the rat brain

    Society for Behavioral Neuroendocrinology 12th Annual meeting 

    Presentation date: 2008

  • Lateral septum regulates expression of estrogen receptor alpha in midbbrain central gray of female rats

    Society for Behavioral Neuroendocrinology 12th Annual meeting 

    Presentation date: 2008

  • Decrease of number of estrogen receptor α-immunoreactive neural cells by a phytoestrogen in female rat hypothalamus

    Society for Behavioral Neuroendocrinology 12th Annual meeting 

    Presentation date: 2008

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Specific Research

  • 生殖機能制御およびその性分化におけるセロトニン神経とエストロゲン受容体

    2008  

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    1.前脳に対する中脳縫線核セロトニン神経投射の量的解析 前脳の排卵、母性行動、雄性行動制御の中心である視索前野(POA)、ロードーシス抑制に関わる外側中隔(LS)、ロードーシス促進に関わる視床下部腹内側核(VMH)に投射する中脳背側縫線核(DR)と正中縫線核(MR)のセロトニン神経細胞数を明らかにするために、去勢雌ラットのそれぞれの部位の右側に逆行性神経トレーサーであるフルオロゴールド(FG)を注入た。凍結切片にFGとセロトニンの二重免疫染色を施し、DRとMRの二重免疫陽性神経細胞数を測定した。その結果、VMHとPOAはDRの反対側から、MRは両側から投射が多いこと、LSは主にMRから投射があることが明らかになった(Neurosci. Res.61(2) 207-218, 2008)。2.視床下部内エストロゲンα受容体発現細胞量の解析 視床下部内のエストロゲン受容体に関しては、排卵と生殖行動に重要とされるα受容体(ERα)の発現細胞数を免疫組織学的に雌雄ラットで調べた。その結果、雌では排卵周期に重要な、VMH、弓状核(ARV)、視索前野前脳室周囲核(AVPvN)、LS, 中脳中心灰白質(MCG)の順でERα免疫陽性細胞数(密度)が多く、雌雄差はVMH雌が大きかった(Soc.for Behav. Neuroendocrinol. 12th Annual meeting, Netherland, July 7-10, 2008 Abstract p.98)現在投稿準備中である。3.セロトニン神経のER発現に対する影響セロトニン神経がERαの発現にどのような影響をもつか、卵巣除去ラットDRを破壊し免疫組織化学的にERα免疫陽性細胞数を計測している。DR破壊するとVMHの免疫陽性細胞数が増加する傾向が見られているが、まだ実験途上で、例数を増やしているところである。

  • 脳の性分化に対する植物含有エストロゲン様物質の影響

    2004  

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    1.脳の性分化にたいする新生期ゲニステイン投与効果: 大豆に含まれるエストロゲン作用物質であるゲニステイン(GS)やダイゼイン(DZ)がラットの脳の性分化に影響を及ぼすかどうかみるため、出生5日間毎日1mgを雌ラットに投与して,膣開口日、膣スメアーによる性周期の確認,卵巣の黄体形成、および、雌型性行動であるロードーシスの発現程度を調べた。対照群として、オイルまたは100μgエストラディオール(E2)を投与した。その結果、E2投与ラットの膣開口日ははやまり、性周期は消失した。また,卵巣は小さくなり黄体が見られなくなった。GS投与雌ラットもE2群と同様に膣開口は早まり、性周期が見られず,小さくなった卵巣に黄体がみられなかった。一方、DZ投与群は,オイル投与対照群と同程度で影響は見られなかった。また、E2投与雌はロードーシスの強さが低下した。GS群は対照群より低い値を示したが、E2ほど大きな低下はみられなかった。DZ群は正常であった。したがって、ゲニステインはラットの脳の性分化にエストラジオールより強くはないが、同様の作用をもつことが示された。2.脳の性分化に対する新生期クメステロール投与効果:クローバに含まれるクメステロール((COM)の脳の性分化への影響を1とほぼ同じ方法で調べた。COM投与はGS投与とは異なり、連日投与ではなく、1mgと3mgを出生5日目のみ1回投与をおこなった。その結果、1mgまたはCOE投与で、E2と同じく、排卵周期が消失し,卵巣には黄体が無かった。ロードーシスに関しては、1mgCOEはほとんど影響がなかったが、3mgCOE群はE2群とほぼ同じ程度に低下した。したがって、クメステロールも脳の雄性化を引き起こす能力があり,ゲニステインより効果が強いことが示された。

  • 脳の性分化における性行動抑制神経機構の役割解明

    2002  

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    1.雌雄ラットの中脳中心灰白質に逆行性トレサ-を注入し、外側中隔中間部の逆行性トレーサー陽性細胞の数を測定した。その結果、雄に比べて、雌において多くみられた。ロードーシス抑制神経細胞の数が雌のほうが多いことを示すものである。2. 雌雄生殖腺除去ラットにおいて、エストロゲンα受容体またはβ受容体の二重免疫染色を行い、中隔外側部の神経細胞におけるエストロゲンの受容体の発現を調べた結果、中隔外側部においては、β受容体含有細胞のほうがα受容体含有細胞より有意に多く、また、どちらもエストロゲンの有無には影響されなかった。対照部位として同様の染色を行った視索前野では、α受容体もβ受容体もあり、α受容体陽性細胞数はエストロゲンがないほうが多かったがβ受容体陽性細胞は変りがなかった。1.と同様な操作を基盤に、逆行性トレ-サ-とβ受容体二重染色を行った結果、二重染色陽性細胞数の逆行性トレーサ陽性細胞総数に対する割合は雌雄とも20パーセント以下で、有意な違いはなかった。3. 外側中隔に存在すると考えられる、GABA,ニューロテンシン、NPY,エンケファリン、などの神経伝達物質の分布を免疫組織化学法で調べた。ニューロテンシン、GABA外側中隔に多量に見られた。また、エンケファリンがある程度見られた。4. ロードーシス抑制力をもつセロトニン神経に関しては、雄雄ラットの前脳におけるセロトニン量を測定した結果、中隔、視索前野、視床下部腹内側核などロードーシス制御に関わるところのセロトニン量は雌のほうが多いことが示された。5. 母性行動の制御に関して、分娩直後の、セロトニンニューロンを多量にもつ正中縫線核の破壊及び腹側部切断がリトリービングやリッキングを強く抑制することから、正中縫線核の重要性が示唆され、論文が国際誌に受理されている。これは母性行動神経機構の性分化を探る基礎データとなる。

  • 中枢神経系による生殖制御とその性分化におけるセロトニンニューロンの役割

    2000  

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     セロトニン神経系は排卵から性行動にいたるあらゆる生殖機能に影響をもつ。本研究ではセロトニン神経細胞を豊富に含む背側縫線核がラットにおける排卵にどのよう役割をもつか、また雌特有の性行動であるロードーシス制御においてエストロゲンとどのような関係にあるか明らかにした。 1.背側縫線核の排卵制御における役割:排卵前日に背側縫線核を破壊したり、セロトニン受容体の拮抗在や作動剤を投与して排卵に対する影響を見た。その結果、背側縫線核を排卵前日の午前中に高周波破壊すると排卵が阻害され、排卵に必用なLHのサージの消失が見られた。また、セロトニンの2A/2C受容体の拮抗であるmianserinを投与しても排卵の抑制が見られた。背側縫線核を排卵前日の午前中に破壊しても、夕刻にセロトニンの2A/2C受容体の作動剤であるDOIを投与すると排卵が回復することも示された。これらの結果から背側縫線核は雌ラットにおける自然排卵制御に不可欠であり、2A/2Cセロトニン受容体を介してその機能を果たしていることが明らかになった(Neurosci. Res. 35, 291-298, 1999)。 2.ロードーシス制御における背側縫線核に対するエストロゲンの影響:背側縫線核はロードーシスの発現に抑制的に働いていることが明らかになっている。また、中隔においても強力な抑制作用がみられることが知られている。雌ラットの背側縫線核か中隔にガイドチューブを移植し、エストロゲンを詰めたチューブを一定時間挿入して、雌の性行動の発現を調べた。その結果、中隔にエストロゲンを入れるとロードーシスの促進が見られたが、背側縫線核に入れても影響はなかった。この結果から、中隔のロードーシス抑制力はエストロゲンで直接解除されるが、背側縫線核の抑制力は直接解除されないことが明らかとなった。したがって、背側縫線核の抑制力のはエストロゲンによって間接的に解除されるか、性ホルモン以外のファクターにより影響を受けるものと考えられる(Neuroendocrinology, 69, 446-452, 1999)。

  • 脊髄と前脳における勃起機能の性分化解明

    1998  

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    ラットの勃起は亀頭のカップ状の変化(亀頭勃起)と陰茎体の反り返り(フリップ、陰茎体勃起)よりなる。ラットの場合は海綿体基部にある球海綿体筋と坐骨海綿体筋に神経を脊髄の球海綿体脊髄核と背外側核が重要な働きをしている。勃起はペニスの皮膚刺激により生じる反射勃起と、発情している雌の存在により生じる非接触性勃起があり、前者は脊髄の機能を中心として、後者は嗅覚-前脳を中心として制御されている。 ペニスや勃起を制御する機構は周生期のアンドロゲンの存在により、発達すると考えられている。本研究は妊娠ラットにアンドロゲンを投与し、さらに生れた雌ラットにアンドロゲンを投与することでペニスを形成させ、勃起機能をはかることで、勃起に関わる末梢器官と中枢神経系の性分化を解明したものである。 妊娠14日目から21日まで1mg,2mgまたは3mgのTestosterone Propionate(TP)を投与し、出生後の雌ラットに出生日から1日おきに8日まで0.5 mgを投与した結果、3mg投与群のすべての雌には雄に近いペニスが形成され、脊髄の球海綿体脊髄核は雄に近いものであった。しかし、2mg投与の雌では30%が正常に近いペニスをもち、残りは不完全なペニスであった。1mgではすべてが不完全なペニスをもっていた。反射勃起は投与アンドロゲン量の増加にともない発現が強まり、非接触性勃起は1mgですでに雄と同じレベルに達し、3mgでも同程度であった。これは、非接触性勃起に必要な脳の機能は1mgTPで発達するが、反射勃起に必要な脊髄の機能は3mgTPを必要とすることを示すが、後者に関してはペニスの発達の度合いを考えると、脊髄のメカニズムも1mgで完成されている可能性は否定できない。この点をさらに明らかにする必要がある。

  • 雄ラットにおけるロードーシス抑制神経回路の解明

    1997  

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    雄ラットを去勢し、大量のエストロゲンを投与しても雌型性行動であるロードーシスはほとんど発現しない。雌ラットにも雄ラットにも、中隔と背側縫線核のセロトニン神経によるロードーシス抑制回路が発達しており、その抑制力の違いにより、雄と雌のロードーシスの発現の違いが生じているものと考えられる。本実験ではその抑制機構の性質の違いを明確にするめに雌と雄ラットの脳に直接エストロゲンを投与しロードーシスの発現を調べた。 麻酔下で雌ラットの卵巣を除去し、中隔または背側縫線核にステンレスガイドチューブを設置する。2週間後、閾値下のエストロゲンを注射し、インナーチューブにエストロゲンかコレステロールをいれ挿入し、ロードーシスの強さをみた。その結果、中隔にエストロゲンをいれるとロードーシスの発現が見られたが、背側縫線核にエストロゲンをいれても生じなかった。コレステロールではどちらの部位ににいれても全く影響がなかった。従って、中隔の抑制力はエストロゲンが直接作用して解除されるが、背側縫線核の抑制機構は直接作用をうけないものと考えられる。次に、雄ラットを去勢し同様の実験を行なった結果、雌ラットとは異なり、中隔にエストロゲンをいれてもロードーシスは生じなかった。 これらの結果より、雄ラットが雌の性行動であるロードーシスをしないのは、中隔にエストロゲンにより解除できないほど強い抑制回路が形成されるためであることが明かとなった。研究成果の発表Lordosis in male rats: Effect of dorsal raphe nucleus cuts. Horm. Behav. 32 (1), 60-67,1997Kakeyama, M. and Yamanouchi, K. Facilitatory effect of ventral cut of dorsal raphe nuclues on lordosis in female rats. Endocrine J. 44 (4) 589-593,1997Kakeyama, M., Negishi, M. and Yamanouchi, K.Inhibitory effect of progesterone on lordosis in male and female rats with septal lesions.In 'Advances in Comparative Endocrinology 2Kawashima, S. and Kikuyama, S.(eds) Monduzzi/Bologna, pp. 1759-1763, 1997.Satou, M. and Yamanouchi, K.

  • ラット排卵・妊娠神経制御における中脳背側縫線核の役割

    1996  

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     ラットの妊娠は下垂体前葉から分泌されるプロラクチンの周期的分泌により、卵巣の黄体からプロゲステロンが分泌されて維持される。妊娠状態は腟の刺激や脳のモノアミン枯渇剤投与により人工的に誘起でき、子宮の脱落膜腫形成により形態的に検証できる。 本実験では人工的な妊娠(偽妊娠)誘起に対して、セロトニンニュ-ロンがどのような影響をもつかセロトニン合成阻害剤であるp-chlorophenylalanine (PCPA)を投与し影響をみ、さらに、セロトニンニュ-ロンの最も豊富な中脳の背側縫線核の働きを破壊により調べた。 正常な4日周期の雌ラットの発情間期Iに1 mg/kg reserpine(R)を投与すると19匹中17のラットに脱落膜腫形成が生じたが、R投与3日前から4回、5 mg/kg PCPAを投与された群では15匹中5匹のみ脱落膜腫がみられた。また、R投与後4回PCPAを投与されても13中6匹で脱落膜腫が形成されたにすぎなかった。この結果より偽妊娠誘起と維持にはセロトニンニュ-ロンの働きが必要であることが示された。 次に雌ラットに背側縫線核か正中縫線核を破壊しておき、R投与または腟刺激によって偽妊娠状態が生じるかどうか検証した。背側縫線核を破壊しておくと、腟刺激をしても15匹中7匹のみで脱落膜腫がみられ、Rを投与しても18匹中10匹のみ脱落膜腫が生じた。一方、正中縫線核を破壊したラットでは、腟刺激でも、Rを投与した場合も、9匹中すべての動物が脱落膜腫を生じた。このように中脳の背側縫線核のセロトニンニュ-ロンが偽妊娠誘起に必須のものであることが示された。 排卵前日の午前中に背側縫線核を破壊すると翌日の排卵が生じなくなる事から、背側縫線核は偽妊娠と同様,排卵に関しても、重要な働きをしていることが示されている。

  • 雌性行動制御神経機構とプロゲステロンの性行動抑制機構

    1995  

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    雌哺乳類の中枢神経系には性行動発現に対する促進神経機構と抑制神経機構が発達している。性行動抑制力は前脳の中隔-視索前野と中脳背側縫線核に存在している。雌哺乳類の性行動はエストロゲンとプロゲステロンが中枢神経系に直接作用し制御を行っている。エストロゲンは中枢神経系内の促進機構と抑制機構に働いて性行動を促進する。一方,プロゲステロンはエストロゲンと同様に雌性行動を促進する働きがあるが,投与するタイミングによってはエストロゲンによって引きおこされる雌性行動が抑制される。すなわちプロゲステロンは発情の停止作用をもつ。本実験ではプロゲステロンによる発情抑制作用が脳がどのような機構と関係しているか,その解明の第一ステップとして,雌性行動抑制機構である中隔,視索前野,背側縫線核との関係を調べた。 雌ラットの卵巣を除去すると同時に,中隔,視索前野,背側縫線核を高周波破壊装置で破壊した。プロゲステロンの抑制作用を見るために5mgのプロゲステロンを5μg/kgのエストラディオールベンゾエート(EB)投与1時間前に注射し,EB投与44時間後に0.5mgのプロゲステロンを投与して性行動を調べた。その結果,中隔,視索前野,背側縫線核を破壊された雌ラットも性行動発現の低下が見られた。この結果から,プロゲステロンは中枢神経系の抑制機構に働いて性行動の抑制をしているのではないことが明らかとなった。さらに,それらの部位を破壊し,雌の性行動を示すようになった雄ラットに,EB投与前にプロゲステロンを注射しても雌性行動の低下が見られた。このように,雄ラットにおいても,プロゲステロンの雌性行動抑制作用がみられることが示された。

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