Surgery (Otolaryngology), 333 Cedar Street, New Haven, CT 06510, USA; Neuroscience, 333 Cedar Street, New Haven, CT 06510, USA; Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
Surgery (Otolaryngology), 333 Cedar Street, New Haven, CT 06510, USA.
Hear Res. 2022 Sep 15;423:108373. doi: 10.1016/j.heares.2021.108373. Epub 2021 Oct 30.
The OHC drives cochlear amplification, and prestin activity is the basis. The frequency response of nonlinear capacitance (NLC), which is a ratiometric measure of prestin's voltage-sensor charge movement (dQ/dV), depends on the location of AC voltage excitation along prestin's operating voltage range, being slowest at the voltage (V) where NLC peaks. Here we directly investigate the coupling between prestin charge movement (Q) and electromotility (eM) at frequencies up to 6.25 kHz, and find tight correspondence between the two at operating voltages displaced from V. Near V, however, eM shows a slower frequency response than Q. We reason that coupling is more susceptible to molecular/cellular loads at V, where prestin compliance is expected to be maximal. Recent cryo-EM studies have begun to shed light on structural features of prestin that impact its performance against loads. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
OHC 驱动耳蜗放大，而 prestin 的活动是基础。非线性电容 (NLC) 的频率响应是 prestin 电压传感器电荷运动 (dQ/dV) 的比率度量，它取决于 AC 电压激励在 prestin 工作电压范围内的位置，在 NLC 峰值处的电压 (V) 下最慢。在这里，我们直接研究了在高达 6.25 kHz 的频率下 prestin 电荷运动 (Q) 和电动性 (eM) 之间的耦合，并在工作电压偏离 V 的情况下发现了两者之间的紧密对应关系。然而，在 V 附近，eM 的频率响应比 Q 慢。我们认为，在 prestin 顺应性预计最大的 V 处，耦合更容易受到分子/细胞负载的影响。最近的冷冻电镜研究开始揭示 prestin 的结构特征，这些特征对其抵抗负载的性能产生影响。本文是由 Joseph Santos-Sacchi 和 Kumar Navaratnam 编辑的《外毛细胞特刊》的一部分。
