| Project/Area Number |
23650165
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Neuroscience in general
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| Research Institution | Nagoya University |
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Principal Investigator |
KOMATSU Yukio 名古屋大学, 環境医学研究所, 教授 (90135343)
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| Project Period (FY) |
2011 – 2012
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| Project Status |
Completed (Fiscal Year 2012)
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| Budget Amount *help |
¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2011: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 経験依存的発達 / 可塑性 / 視覚野 / サイトカイン / スケーリング / 長期増強 / T型Ca2+チャネル / 神経科学 / 脳・神経 / シナプス可塑性 / 眼優位可塑性 |
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| Research Abstract |
In rodents, monocular deprivation produces depression of visual cortical responses evoked by the stimulation of deprived eye at 3 days after the start of the deprivation during the critical period of visual cortical development, and produces potentiation of visual cortical responses evoked by the stimulation of non-deprived eye when the deprivation is continued for 4 or more days. The potentiation is prevented by the blockade of T-type Ca2+ channel-dependent long-term potentiation (T-LTP). The potentiation is also prevented by a deficiency of TNF-α, which is known to mediate the increase of quantal amplitude of excitatory synaptic currents via the synaptic scaling mechanism. These observations suggest that the potentiation of non-deprived eye responses is mediated by either T-LTP or synaptic scaling. I investigated these two possibilities in this study. Visual cortical slices were prepared from rats after 3 or 6 days of monocular deprivation and from control rats, and miniature excitatory synaptic currents (mEPSCs) were recorded from layer 2/3 pyramidal cells in the binocular region using the whole-cell recording method. No significant differences were found in the mEPSC amplitude between the 3 groups of rats, indicating that monocular deprivation did not initiate synaptic scaling. In rat visual cortical slices, the pharmacological blockade of the action of TNF-α prevented T-LTP production. In slices prepared from TNF-αknockout mice, T-LTP did not occur and it was rescued by the addition of TNF-α. These results demonstrate that TNF-α is required for the production of T-LTP and suggest that the failure of potentiation of non-deprived eye responses in TNF-α knockout mice is ascribed to the deficiency of T-LTP, but not synaptic scaling.
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