異なるタイプのカルシウムチャネルが中央シナプス伝送を媒介する
1Department of Physiology, Kyoto University Faculty of Medicine, Japan.
Nature
|November 11, 1993
まとめ
電圧に依存するカルシウムチャネルがシナプス伝送を媒介する. P型およびN型カルシウムチャネルは,中枢神経系の神経伝達物質の放出に関与し,P型チャネルはより重要な役割を果たします.
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
背景:
- シナプス伝播は,プレシナプス端末の電圧依存カルシウムチャネル経由のカルシウム流入に依存しています.
- 中枢シナプスで神経伝達物質の放出を司るカルシウムチャネルの特定のサブタイプは,ほとんど特徴づけられていない.
研究 の 目的:
- 哺乳類の中枢神経系におけるシナプス伝達を媒介するカルシウムチャネルの特定のサブタイプを特定する.
- 刺激性および阻害性ポストシナプス電流におけるN型およびP型カルシウムチャネルの役割を調査する.
主な方法:
- オメガ-コノトキシンGVIA (N型) とオメガ-アガ-IVA (P型) を含む,タイプ固有のカルシウムチャネルブロッカーを,ポストシナプス電流で使用した.
- ネズミの小脳,脊髄,海馬の薄い切片でポストシナプス電流を記録した.
- L型カルシウムチャネルブロッカーのニカルディピンの効果を評価した.
主要な成果:
- オメガ-アガ-IVAは,小脳と脊髄の神経細胞の抑制性ポストシナプス電流と,海馬の神経細胞の刺激性ポストシナプス電流を顕著に抑制しました.
- オメガコノトキシンGVIAは,これらのポストシナプス電流を部分的に抑制しました.
- ニカルディピンはシナプス伝達に有意な効果を示さなかった.
結論:
- 少なくとも2種類のカルシウムチャネル,主にP型とN型は,哺乳類の中央神経系におけるシナプス伝達を媒介する.
- P型カルシウムチャネルは,N型チャネルと比較してシナプス伝送を媒介する上でより支配的な役割を果たしているようです.
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