| Project/Area Number |
05404086
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neuroscience in general
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| Research Institution | Kyoto Pref. Univ. of Med. |
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Principal Investigator |
TOYAMA Keisuke Kyoto Pref. Univ. of Med. Dep. of Physiol. Prof., 医学部, 教授 (90090505)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Nobuhiko Osaka Univ. Dep. Of Biophysical engineering Associative Prof., 基礎工学部, 助教授 (00191429)
HIGASHI Shuji Kyoto Pref. Univ. of Med. Dep. of Physiol. Assistant Prof., 医学部, 助手 (30228704)
KUROTANI Tohru Kyoto Pref. Univ. of Med. Dep. of Physiol. Associate Prof., 医学部, 講師 (50195591)
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| Project Period (FY) |
1993 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥29,500,000 (Direct Cost: ¥29,500,000)
Fiscal Year 1996: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1995: ¥10,900,000 (Direct Cost: ¥10,900,000)
Fiscal Year 1994: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1993: ¥12,900,000 (Direct Cost: ¥12,900,000)
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| Keywords | Self-organization, / Development, / Visual cortex, / Plasticity, / Long term potentiation, / Laminar structures, / Gene transcription, / Coculture preparation / コバリアンス学習 / 共培養標本 |
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| Research Abstract |
How is the cortical circuitry constructed (self-organized) by interaction between gene and learning mechanisms? This has been one of the central problems in the developmental neurobiology. This study revealed that the development of the laminar structures in the visual cortex (VC) specifying what targets neurons in a particular layr are connected to, totally depend on the gene mechanisms. All laminar structures in the normal VC are reproduced in the coculture preparations where a block of the lateral geniculate nucleus and a VC slice of infant rats were cultured together.
Another finding of the present study is demonstration of two types of long term potentiation (LTP) in rat VC,i. e., 1) slow LTP (sLTP) which had a slow time course and was only induced in infant rats, and 2) fast LTP (fLTP) which had a fast time course and was induced both in infant and adult rats. Induction of sLTP depended on Ca entry through voltage gated Ca channels, gene transcription as well as protein synthesis and was expressed in the geniculo-cortical synapses, while that of fLTP depended on Ca entry through NMDA channels and was expressed in the axon collateral synapses of the cortical efferents. These observations indicate that sLTP underlies the developmental plasticity for formation of the columnar structures in infant VC,while fLTP is the basis for the plasticity in adult VC.
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