Details of a Researcher - EDAGAWA, Yoshikuni

Advanced Micro Fluidic Engineering and Its Applications for High Sensitive Quantitative Measurements of Biomolecules

Project Year :

2011.05

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2016.03

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In this study, the noble microfluidic device technology was developed in order to enable the optical high sensitive quantitative measurement of the micro luminescent sample as follows. 1) The micro droplet manufacturing technology of the various size. 2) The control technology of the micro flow. 3) The passive sorting technology of the micro droplet. Next, the measurement of the micro luminescent samples by systematizing microfluidic device was realized. 1) Insert a living cell to a droplet one by one, and analyze the gene of the environmental microbe. 2) Observation cellular growth and evaluate enzymatic reaction activity. Optical quantitative measurement was realized by this study
Acquisition of location-specific information of neuronal cell death and elucidation of contribution of the microdomains of the cell

Project Year :

2011.04

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2014.03

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This study was designed by using the microsystem in order to obtain the location-specific information of cell death in single cells in culture and to examine the contribution of cell micro-domains to it. The microfluidic device developed in the present study enabled to no-invasive capture and culture of isolated single cells in the micro-environment. And the system realized to monitor the process of the cell death induced by the localized stress exposed with a laminar flow of chemical fluid. The present study suggest that a microdomain of a cell projection played a critical role in inducing the apoptotic cell death, because the chemical stress of that was confirmed to be sufficient to induce expression of activated caspase-3 as an effector caspases of apoptosis in the vicinity of the cell nucleus
Construction of Integrated Management Method and Multi-Layer Model for Generation of "Sense of Harmony" among Various Modal Information Connected under Relations with Color as a Common Axis

Project Year :

2011

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2013

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In this study, we investigated the generation mechanism of "sense of harmony" which is generally felt by the human. In particular, we have launched the study on a basic research to provide the connection among various modal information and the study on their applications to the real environment. One of the most distinguish feature of this study is that we have positioned "color" as an intermediate language to connect various modal information. The main results of this study are as follows. (1) some basic findings on the generation mechanism of "sense of harmony", (2) some general findings on how to construct of harmonic space, (3) some basic findings on the generation mechanism of "sense of harmony" from the brain science viewpoint, (4) construction of an ontology for the integrated management of "a sense of harmony". The development of an integrated management system of "sense of harmony" based on the outcomes of this study is our challenging future work.
Molecular mechanisms of synaptic plasticity at visual cortical inhibitory synapses

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We studied molecular mechanisms underling long-term potentiation (LTP) and long-term depression (LTD) at inhibitory synapses in developing rat visual cortex, and obtained following results.1. Inhibition of postsynaptic phospholipase C, IP_3 receptors or Ca^<2+> increase prevented the generation of LTP as did the blockade of GABA_B receptors. In addition, blockade of alphal adrenoceptors or 5-HT_2 receptors, which are coupled with IP_3 formation, reduced incidence of LTP.These results suggest that LTP induction requires the activation of postsynaptic GABA_B receptors and that its effect is mediated at least partly by facilitation of the monoamine-induced IP_3 formation, which then causes Ca^<2+> release from the internal stores in postsynaptic cells.2. LTD was produced by repetitive firing of cells elicited by a postsynaptic injection of depolarizing current pulses. Induction of LTD was blocked by bath application of the L-type Ca^<2+> channel inhibitor nifedipine or by postsynaptic loading of a Ca^<2+> chelator BAPTA.In addition, LTD was produced by flash photolysis of caged Ca^<2+> in postsynaptic cells. These results suggest that postsynaptic Ca^<2+> increases due to the activati
大脳皮質視覚野における長期増強のシナプス前機構の解析

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発達期の大脳皮質視覚野では興奮性シナプスだけでなく抑制性シナプスにも長期増強が生じる。両長期増強の誘発にシナプス後細胞におけるCa^<2+>濃度の上昇が必要であることはすでに確立されている。興奮性シナプスの長期増強の発現部位は不明であるが、抑制性シナプスの長期増強はシナプス前側に発現することを示唆する結果を得ている。本研究では、薬理学的に興奮性シナプス伝達を遮断したラット視覚野切片標本においてホールセン・パッチクランプ法により抑制性シナプスの長期増強のシナプス前機構を解析した。その結果、長期増強の維持にシナプス前細胞の電気的活動が必要であることが明らかとなった。シナプス前線維の高頻度刺激により誘発された長期増強はテスト刺激を30分間停止するとテスト刺激再開後約60%の細胞で反応の大きさがコントロール・レベルに戻り、増強は消失した。長期増強を誘発してからTTXを加えてシナプス前細胞の活動を一時的に停止してから洗