哺乳類の毛束による力生成は,頭増幅の役割をサポートしています

H J Kennedy¹, A C Crawford, R Fettiplace

¹Department of Physiology, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA.

Nature

|February 8, 2005

まとめ

哺乳類の聴覚増幅には,外側の毛細胞 (OHC) の毛束が力を生み出すことも含まれます. この代替メカニズムは,体内の電動性とは異なり,高周波で動作し,頭機能を向上させることができる.

科学分野:

聴覚神経科学とは
機械生物学のメカノバイオロジー
細胞生理学細胞生理学

背景:

哺乳類の聴覚の敏感性は,コクリアの機械的増幅に依存しています.
外部毛細胞 (OHCs) は,体内の電動性を介してこの増幅を提供すると仮定されています.
プレスティンベースの電動性モデルには,高周波の制限があります.

研究の目的:

哺乳類OHCにおける代替力生成メカニズムを調査する.
頭増幅におけるOHC毛束の役割を調査する.
OHCヘアバンドルが高周波で力を生成できるかどうかを判断する.

主な方法:

OHC受容体ポテンシャルを記録するために,パッチクランプ電気生理学を使用しました.
OHCの毛束に機械的刺激を適用した.
サブミリ秒の時間スケールでOHCヘアバンドルによる力発生を測定した.

主要な成果:

哺乳類のOHC毛束は,ミリ秒未満の時間スケールで力を生み出すことができます.
この力発生は,メカニカルトランスデューサーのチャネル適応に関連しています.
毛束のモーターメカニズムは,高周波で動作することがあります.

結論:

哺乳類のOHCには新しい力発生器が存在する.
OHCヘアバンドル・フォース・ジェネレーションは,潜在的に高周波の増幅メカニズムを提供する.
この発見は,頭増幅における体電気運動性の補完的な役割を示唆しています.

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