深層の皮質層は,タラムスによって直接活性化されます
Christine M Constantinople1, Randy M Bruno
1Department of Neuroscience and Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA.
まとめ
感覚情報は,層4 (L4) だけでなく,深い層 (L5/6) への直接のタラモコルチカル (TC) シナプス経由で皮質に到達します. これは脳内の並列処理の流れを明らかにします.
科学分野:
- 神経科学は神経科学である.
- 皮質回路は,皮質回路である.
- 感覚処理は,感覚を処理するプロセスです.
背景:
- タラモコルティカル (TC) 投影は,皮質への感覚情報の主要な経路です.
- 感覚情報は層4 (L4) から他の皮質層 (L2/3,L5/6) に伝播すると広く信じられていた.
研究 の 目的:
- タラムスから深層の皮質層 (L5/6) への直接のシナプス入力を調べる.
- 層4 (L4) が,L5/6ニューロンへの感覚情報の強制的なリレーであるかどうかを判断する.
主な方法:
- ネズミにおけるin vivo電気生理学的記録.
- タラミックニューロンとL5/6ニューロンからのペアリング記録.
- 層4 (L4) の薬理学的不活性化
主要な成果:
- 多くのL5/6ニューロンは,L4応答に類似した遅延で,直接のTCシナプス入力を示した.
- 直接的なTCシナプスが,特にL5Bの様々な亜粒子のニューロンに,実質的に収束している.
- L4の不活性化は,L5/6ニューロンへの感覚誘発のシナプス入力に影響を与えなかった.
結論:
- 層4 (L4) は,感覚皮質活動のための強制的な配送ハブではありません.
- タラムスは,別々の平行な皮質処理ストリームを活性化し,L4とL5/6の両ニューロンを直接標的にします.
- これは,皮質内の階層的な情報フローに関する伝統的な見解に異議を唱える.
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