Motility-associated hair-bundle motion in mammalian outer hair cells
Motility-associated hair-bundle motion in mammalian outer hair cells
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DOI：
10.1038/nn1509
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发表时间：
2005-08-01
影响因子：
25
通讯作者：
He, DZZ
中科院分区：
文献类型：
--
作者：
Jia, SP;He, DZZ
哺乳动物的听力由于耳蜗内的局部机械反馈过程而具有显着的敏感度和频率选择性。耳蜗外毛细胞是反馈环中的关键成分，其快速的躯体运动被认为是耳蜗放大的来源。另一种观点认为，放大来自活跃的发束运动，类似于在非哺乳动物毛细胞中看到的。我们测量了电压诱发的沙土鼠耳蜗的发束运动，以确定这种运动是否也存在于哺乳动物的毛囊细胞中。细胞呈束状运动，最大响应波长达830 nm。这种运动对通常会阻止立体纤毛中的机械转导的操作不敏感，在新生儿内分泌细胞和预基因敲除的内分泌细胞中也不存在。这些发现表明，束运动起源于躯体运动，并且躯体运动在哺乳动物的耳蜗声放大中起着中心作用。
Mammalian hearing owes its remarkable sensitivity and frequency selectivity to a local mechanical feedback process within the cochlea. Cochlear outer hair cells (OHCs) function as the key elements in the feedback loop in which the fast somatic motility of OHCs is thought to be the source of cochlear amplification. An alternative view is that amplification arises from active hair-bundle movement, similar to that seen in nonmammalian hair cells. We measured voltage-evoked hair-bundle motions in the gerbil cochlea to determine if such movements were also present in mammalian OHCs. The OHCs showed bundle movement with peak responses of up to 830 nm. The movement was insensitive to manipulations that would normally block mechanotransduction in the stereocilia, and it was absent in neonatal OHCs and prestin-knockout OHCs. These findings suggest that the bundle movement originated in somatic motility and that somatic motility has a central role in cochlear amplification in mammals.