Dynamics and molecular mechanism of activity-dependent neuronal plasticity
Project/Area Number |
15500259
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Neurochemistry/Neuropharmacology
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Research Institution | Osaka University |
Principal Investigator |
SHIMEGI Satoshi Osaka University, Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (20271033)
|
Project Period (FY) |
2003 – 2005
|
Project Status |
Completed (Fiscal Year 2005)
|
Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
Keywords | Protein Kinase A / マスキング / 並列情報処理 / 初期視覚 / 眼優位性 / 方位選択性 / プロテインキナーゼA / ネコ / ムシモール / 臨界期 |
Research Abstract |
Monocular deprivation (MD) during the critical period for the development of visual cortex causes a loss of binocular response of neurons and a shift to the open eye, a normal ocular dominance (OD) shift. However when MD is combined with chronic inactivation of the visual cortex by muscimol, the OD distribution of the neurons shifts to the deprived eye (reverse OD shift). We have previously shown that the normal OD shift is abolished by chronic infusion of the protein kinase A (PKA) inhibitor, 8-chloroadenosine-3_-, 5_--cyclic monophosphorothioate, Rpisomer (RP-8-Cl-cAMPS), into kitten visual cortex. In this study, we investigated the effect of this inhibitor on the reverse OD shift. Combination of MD and muscimol infusion into the visual cortex of 6-wk-old kittens caused a reverse OD shift that was comparable to that seen in previous studies. However, a reverse OD shift was also seen with concurrent infusion of the PKA inhibitor with muscimol. The strongest OD shift was observed in layer IV regardless of the presence or absence of the PKA inhibitor. This suggests that the dissociation of pre- and postsynaptic activities, which occurs mainly at thalamocortical synapses, induces the reverse OD shift and that inhibition of PKA does not prevent it. Presumably, an inhibition of PKA has no effect in silent cortex. We conclude that 1) an activation of PKA is not required for the induction of the reverse OD shift, and 2) the intracellular signaling mechanism underlying MD-induced OD plasticity differs between normal and reverse OD shifts.
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Report
(4 results)
Research Products
(9 results)