光は,リムルスの内側光受容体内の電圧依存のカリウムチャネルを調節する

R J Leonard, J E Lisman

Science (New York, N.Y.)

|June 12, 1981

まとめ

光への曝露は,主要電圧ゲートカリウムチャネルである遅延整流器を遮断することによって,細胞内の外向きの電流を減少させます. この調節は,恒常的な光の中でセル電圧を安定させるのに役立ちます.

科学分野:

細胞電気生理学細胞電気生理学
写真生物学写真生物学
イオンチャネル機能のイオンチャネル機能

背景:

電圧に依存するイオン電流は,細胞の電気信号伝送に不可欠です.
光は様々なメカニズムを通じて細胞機能に影響を与えることができます.
遅延整流器のカリウム電流は,膜再極化に重要な役割を果たします.

研究の目的:

光が電圧に依存する外向きの電流に与える影響を調査する.
光調節によって影響を受ける特定のイオンチャネルを特定するために.
光による電流変化の機能的結果を理解する.

主な方法:

電気生理学的記録 (電圧ランプ) 暗闇と照明後の記録.
テトラエチラモニウム (TEA) がカリウムチャネルを遮断するために用いられる.
電流-電圧関係と膜伝導性の分析.

主要な成果:

照明は,暗闇で測定された電圧に依存する外向きの電流を大幅に減少させた.
この光による減少はテトラエチルアモニウムによって阻害され,カリウムチャネルが関与していることを示しています.
電流の減少は,全膜伝導率の減少と関連していました.
光調節電流の電圧依存は,遅延整流器のカリウム電流の電圧依存と一致した.

結論:

光は,遅延直流器のカリウム電流を積極的に調節する.
この調節は,恒常的な照明下で安定した膜電位を維持するのに役立ちます.
この発見は,細胞興奮性を影響する新しい光調節メカニズムを明らかにしています.

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