The Spatial Pattern of Cochlear Amplification
The Spatial Pattern of Cochlear Amplification
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DOI：
10.1016/j.neuron.2012.09.031
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发表时间：
2012-12-06
期刊：
影响因子：
16.2
通讯作者：
Hudspeth, A. J.
中科院分区：
文献类型：
--
作者：
Fisher, Jonathan A. N.;Nin, Fumiaki;Hudspeth, A. J.
感觉神经性听力损失主要是由于机械感觉毛细胞的故障引起的，它改变了沿耳蜗声信号传输的行波。然而，耳蜗力学和毛细胞的放大功能之间的联系仍然不清楚。使用一种光学技术，允许有针对性地灭活prestin，一种外毛细胞的蛋白质，在基底膜上产生作用力，我们证明这些作用力与耳蜗行波局部相互作用，实现巨大的机械放大。通过扰动基底膜狭窄部分的放大，我们进一步证明了耳蜗行波在接近峰值时积累了增益。对这些结果的分析表明，耳蜗放大产生的负阻尼能抵消粘性阻力阻碍行波的作用；靶向光灭活局部中断了这种补偿。这些结果揭示了耳蜗行波的放大轨迹，并将正常听力的特征与分子作用力联系起来。
Sensorineural hearing loss, which stems primarily from the failure of mechanosensory hair cells, changes the traveling waves that transmit acoustic signals along the cochlea. However, the connection between cochlear mechanics and the amplificatory function of hair cells remains unclear. Using an optical technique that permits the targeted inactivation of prestin, a protein of outer hair cells that generates forces on the basilar membrane, we demonstrate that these forces interact locally with cochlear traveling waves to achieve enormous mechanical amplification. By perturbing amplification in narrow segments of the basilar membrane, we further show that a cochlear traveling wave accumulates gain as it approaches its peak. Analysis of these results indicates that cochlear amplification produces negative damping that counters the viscous drag impeding traveling waves; targeted photoinactivation locally interrupts this compensation. These results reveal the locus of amplification in cochlear traveling waves and connect the characteristics of normal hearing to molecular forces.