ニューロンネットワークの混沌と,バランスのとれた刺激活動と阻害活動の混沌
C van Vreeswijk1, H Sompolinsky
1Racah Institute of Physics and Center for Neural Computation, Hebrew University, Jerusalem, 91904 Israel.
Science (New York, N.Y.)
|December 6, 1996
まとめ
神経ネットワークは,バランスの取れた興奮と抑制により,混乱したダイナミクスを示し,刺激に対する迅速な反応につながります. これは,動物の皮質ニューロンで観察された不規則な発火パターンを説明します.
科学分野:
- 神経科学は神経科学である.
- コンピューティング神経科学
- 理論的な神経科学
背景:
- 行動する動物の皮質ニューロンは,一時的に不規則なスパイキングを示します.
- この発火不規則の背後にある理由と,その機能的意義は不明である.
研究 の 目的:
- 神経細胞発火の時間的な変動は,刺激と阻害の入力とのバランスから生じるという仮説を調査する.
- このバランスがニューラル処理とネットワークダイナミクスに及ぼす影響を調査する.
主な方法:
- ニューロンネットワークのダイナミクスの理論的調査.
- 稀少で強いシナプス結合を持つ刺激性および抑制性ニューロン集団の大規模なネットワークをモデル化.
- 一定の外部入力下でのネットワーク行動の分析.
主要な成果:
- このようなネットワークでは,刺激的および抑制的インプットの間のほぼバランスが自然に発生します.
- バランスの取れた状態は,外部からのインプットが恒常的であっても,非常に混沌としたダイナミクスによって特徴付けられます.
- 非線形単一ニューロンダイナミクスにもかかわらず,ネットワークは刺激に対して線形反応を示します.
- ネットワークは,個々のニューロンの統合時間よりも速い時間スケールで外部刺激に反応します.
結論:
- バランスの取れた興奮と抑制は,皮質ニューロンの発火における時間的変動の妥当な源である.
- バランスの取れたネットワークの混沌としたダイナミクスは,効率的かつ迅速な情報処理につながる可能性があります.
- これらの発見は,皮質ネットワークが複雑なダイナミクスと応答的行動の両方をどのように達成するかのメカニズムを示唆しています.
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