Coherent motion of stereocilia assures the concerted gating of hair-cell transduction channels
Coherent motion of stereocilia assures the concerted gating of hair-cell transduction channels
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DOI：
10.1038/nn1818
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发表时间：
2007-01-01
影响因子：
25
通讯作者：
Hudspeth, A. J.
中科院分区：
文献类型：
--
作者：
Kozlov, Andrei S.;Risler, Thomas;Hudspeth, A. J.
毛细胞的机械感受细胞器，即发束，是高度敏感的，因为它的转导通道在非常窄的位移范围内打开。转导通道的同步门控也是放大和调整反应性的活跃发束运动的基础。独立转导通道的门控协调程度取决于单个静纤毛作为一个单元移动的紧密程度。在牛蛙的球囊中使用双光束干涉测量法，我们发现静纤毛的热运动与发束相对边缘相距很远，显示出高相干性和可忽略不计的相位滞后。由于静纤毛的机械自由度受到强烈约束，因此施加在发束中任何位置的力都会使该结构作为一个整体发生偏转。这一功能确保了传导通道的协调门控，从而最大限度地提高了机电传导的灵敏度，并增强了发束放大其输入的能力。
The hair cell's mechanoreceptive organelle, the hair bundle, is highly sensitive because its transduction channels open over a very narrow range of displacements. The synchronous gating of transduction channels also underlies the active hair-bundle motility that amplifies and tunes responsiveness. The extent to which the gating of independent transduction channels is coordinated depends on how tightly individual stereocilia are constrained to move as a unit. Using dual-beam interferometry in the bullfrog's sacculus, we found that thermal movements of stereocilia located as far apart as a hair bundle's opposite edges showed high coherence and negligible phase lag. Because the mechanical degrees of freedom of stereocilia are strongly constrained, a force applied anywhere in the hair bundle deflects the structure as a unit. This feature assures the concerted gating of transduction channels that maximizes the sensitivity of mechanoelectrical transduction and enhances the hair bundle's capacity to amplify its inputs.