成人の主視野皮質における受容場動態

C D Gilbert¹, T N Wiesel

¹Rockefeller University, New York, New York 10021-6399.

Nature

|March 12, 1992

まとめ

大人の脳は,網膜の損傷の後,視覚皮質を急速に再編成します. 入信信号だけでなく,皮質の可塑性が,この回復を駆動し,固有のシナプス変化を強調します.

科学分野:

神経科学は神経科学である.
神経可塑性とは
視覚システム研究視覚システム研究

背景:

大人の脳は有意な可塑性を発揮し,変化した感覚入力に反応して皮質のトポグラフィを適応させます.
以前の研究では,感覚的欠乏が時間とともに受容場サイズと皮質マップを修正することが示されています.

研究の目的:

網膜病変による視覚入力除去後の即時および長期の皮質の再編成を調査する.
視覚皮質の皮質回復と地形再編成の基礎となるメカニズムを決定する.

主な方法:

成人の被験者における誘発的焦点双眼網膜損傷.
損傷の前と直後に同じ皮質部位から記録された.
ゲニキュロコーティカルアフェレントの広がりを評価するための解剖学的研究を行いました.

主要な成果:

網膜スコトーマの近くの皮質細胞の受容場サイズが,即座に大きく増加することが観察されました.
以前に静止されていた皮質の領域における視覚活動の回復を数ヶ月以内に実証した.
lateral geniculate nucleusが大きな静かな領域を保持し, afferent spreadが皮質回復を説明するのに不十分であったことを発見しました.

結論:

網膜損傷後の視野皮質のトポグラフィック再編成は,主に皮質内の内在のシナプス変化によって引き起こされます.
皮質内の長距離の水平接続は,この適応的可塑性において重要な役割を果たしている可能性が高い.
この発見は,アフェレント入力再構成のみに基づいた説明に異議を唱える.

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