背脊脊髄損傷後の体感覚皮質の非活性化および再活性化

N Jain¹, K C Catania, J H Kaas

¹Department of Psychology, Vanderbilt University, Nashville, Tennessee 37240, USA.

Nature

|April 3, 1997

まとめ

背骨柱は,脳の体感覚皮質に感覚情報を伝達するために不可欠です. これらの経路の損傷は,他の脊髄経路が補償することなく,脳のプロセスがどのように接触するかに重大な,長期的な変化をもたらします.

科学分野:

神経科学は神経科学である.
ソマトセンサリーシステム研究

背景:

脊髄の背中の柱は,伝統的に脳への体感覚情報の主要な経路と考えられています.
背柱の病変の機能的影響は議論されており,報告された結果は大きく異なる.

研究の目的:

主要体感覚皮質 (領域3b) の活性化のために背柱アフェレンスの必要性を調査する.
脊柱の病変が皮質の可塑性や感覚の再マッピングに及ぼす影響を調べる.

主な方法:

動物モデルの頸椎背骨の切断 (完全または部分).
手の刺激に対する対側主体体感覚皮質 (領域3b) のニューロン反応を記録する.
機能的回復と感覚の再マッピングを長期にわたって (数週間から数ヶ月) 評価する.

主要な成果:

背骨の完全な切断は,エリア3bのニューロンの手刺激に対する反応を直ちに廃止しました.
部分的な切断は,時間とともに残りのアフェレンツの皮質表現の拡大につながった.
長期の回復の後,エリア3bの剥奪された手の表現は,顔の入力に反応するようになりました.

結論:

主要体感覚皮質の領域3bは,正常な機能のために背骨柱の入力に極めて依存しています.
他の脊髄経路は,損傷後の背骨柱を効果的に置き換えることはできません.
背骨の損傷後に重要な皮質のリマッピングが起こりますが,これは被災した身体部位からの正常な感覚処理を回復しません.

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