| Project/Area Number |
17390058
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General physiology
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| Research Institution | National Institute for Physiological Sciences |
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Principal Investigator |
NABEKURA Junichi National Institute for Physiological Sciences, Department of Developmental Physiology, Professor, 発達生理学研究系, 教授 (50237583)
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| Co-Investigator(Kenkyū-buntansha) |
MAEJIMA Takashi National Institute for Physiological Sciences, Department of Developmental Physiology, Assistant Professor, 発達生理学研究系, 助教 (70399319)
WATANABE Miho National Institute for Physiological Sciences, Department of Developmental Physiology, Research Associate, 発達生理学研究系, 特任助教 (10399321)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥12,000,000 (Direct Cost: ¥12,000,000)
Fiscal Year 2006: ¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 2005: ¥7,100,000 (Direct Cost: ¥7,100,000)
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| Keywords | GABA / glycine / development / transmitter / auditory / switching / グリシン / GABAB受容体 / スイッチング / 聴覚 / 神経終末 / 抑制系 |
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| Research Abstract |
In order to elucidate the functional implication of inhibitory transmitter switching occurring at auditory relay nucleus of brain stem, we employed electrophysiological and immunohistochemical approach of GABA_B receptor expression over the developmental period. There was a concomitant developmental reduction in the density of expression of the GABAB receptor subunits, R1 and R2, and we also observed a developmental change in the expression pattern of R1 from neurons to astroglia. The GABAB receptor mediated increase in postsynaptic K^+ conductance showed a dramatic reduction over the same period. We have therefore shown that, around the onset of hearing in rats (about 10 days after birth) there is a dramatic reduction in both GABAB receptor expressions in LSO neurons and in the functional effects of GABA_B receptor activation i.e. increased membrane K^+ conductance. It is known that inhibitory input into the LSO changes from being GABAergic to being glycinergic around the onset of hearing ; our results indicate that GABA_B receptor mediated inhibition also shows developmental plasticity. In addition to the well-described developmental change of GABA_A receptor mediated responses from depolarizing to hyperpolarizing, the current data provides a novel and additional example of developmental changes in GABAergic neurobiology.
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