Synaptic modifications induced by monocular deprivation in visual cortex

Research Project

Project/Area Number	16K07012
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Neurophysiology / General neuroscience
Research Institution	National Institute for Physiological Sciences
Principal Investigator	Komatsu Yukio 生理学研究所, 基盤神経科学研究領域, 特別協力研究員 (90135343)
Project Period (FY)	2016-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000) Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	経験依存的発達 / 眼優位可塑性 / シナプス可塑性 / 視覚野 / 片眼遮蔽 / 神経可塑性
Outline of Final Research Achievements	I investigated monocular deprivation (MD)-induced modifications of synaptic inputs on layer 2/3 pyramidal cells of visual cortex during the critical period, using visual cortical slices prepared following monocular deprivation. I conducted whole-cell recording experiments and analyzed unitary excitatory postsynaptic currents (uEPSCs) evoked in these cells by focal glutamate uncaging with laser scanning photostimulation. Non-deprived eye dominant cells were discriminated from deprived eye dominant cells, based on the level of GFP expressed by monocular visual stimulation. The uEPSCs decreased in number in deprived eye-dominant cells after 3 days of MD, and increased in number and amplitude in non-deprived eye dominant cells after 6 days of MD. The changes in the latter cells did not occur in TNFα-deficient mice, which lacks T-type Ca2+-channel dependent long-term potentiation (T-LTP), suggesting that T-LTP mediates the potentiation of visual responses to non-deprived eye stimulation.
Academic Significance and Societal Importance of the Research Achievements	シナプス可塑性は発達期の経験依存的機能発達の基盤と考えられている。眼優位可塑性はこの発達の神経機構の解析に適したモデルと考えられ、多くの研究に用いられてきた。しかし、眼優位性は麻酔下の動物での視覚実験で調べられ、シナプス可塑性はスライス標本で調べられてきたので、眼優位可塑性の基盤をなすシナプス可塑性が視覚野内のどのシナプスで起こり、どのタイプのものであるかはか不明であった。本研究結果はこの問題の解明に寄与するものと考えられる。