EPSPの有効性が新皮質のピラミダニューロンにおけるシナプスの位置に依存している
Stephen R Williams1, Greg J Stuart
1Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT 0200, Australia.
Science (New York, N.Y.)
|March 9, 2002
まとめ
ニューロンへの遠隔シナプス入力は弱いが,同時に活性化するとアクションポテンシャルを誘発する. この偶然の検出は,遠端刺激性ポストシナプスポテンシャル (EPSP) の一時的なシグナル伝達役割を強調しています.
科学分野:
- 神経科学は神経科学である.
- 計算神経科学とは
- 細胞神経科学は細胞神経科学である.
背景:
- ニューロンは,複雑な樹状樹木にわたって何千ものシナプス入力を統合します.
- 異なる dendritic 場所のシナプス入力がニューロンの出力にどのように影響するかを理解することは非常に重要です.
研究 の 目的:
- 新皮質のピラミッド神経細胞の特定のデンドリット部位で生成される刺激性ポストシナプスポテンシャル (EPSP) の体効果を調査する.
- 遠隔シナプス入力がニューロンの発火に影響を与える条件を決定する.
主な方法:
- 新皮質のピラミダニューロンからの電気生理学的記録.
- 既知のデンドリット部位におけるシナプスインプットの刺激.
- ソマティックEPSPの振幅とアクションポテンシャル出力の分析.
主要な成果:
- ソマティックEPSPの振幅は,ソマからの入力距離が増加するにつれて著しく減少しました.
- EPSPの使用依存うつ状態は,より遠隔の入力に対して増加した.
- 狭い時間枠内での遠隔EPSPの偶発的な活性化 (約. 10 ms) は,顕著な衰弱 (>40倍) にもかかわらず,アクションポテンシャル出力を直接駆動することができます.
- デンドリティックスパイク生成は,偶然の遠端入力活性化後に観察されました.
結論:
- ディスタルのEPSPは,背景の体的興奮の非効率的な源である.
- 遠隔のEPSPの偶然検出は,アクションポテンシャル生成における強力で一時的なシグナル伝達役割を可能にします.
- dendritic 統合とスパイク生成は,神経の出力に遠隔入力を翻訳する上で重要な役割を果たします.
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