Lukashkin A N, Russell I J
School of Biological Sciences, University of Sussex, Falmer, Brighton, UK.
Hear Res. 1997 Nov;113(1-2):133-9. doi: 10.1016/s0378-5955(97)00135-4.
The fast outer hair cell (OHC) electromotility is voltage dependent and is driven by changes in the OHC transmembrane potential. Those changes include the receptor potential generated by the variable conductance of the mechanoelectrical transducer (Evans and Dallos, 1993). In the experiments described here, we show that the voltage dependence of the mechanoelectrical transducer influences the low frequency motile responses of OHCs to an external electrical field. OHCs were fully inserted into a glass suction pipette, the microchamber, so that only the cuticular plate and hair bundle were exposed to the bath solution. With this technique, a rectification of the mechanical response, equivalent to an excitatory displacement of the hair bundle, was observed when the command voltage inside the microchamber depolarized the apical membrane. The shape of the response persisted when the OHC voltage-gated conductances were blocked. Following treatment of the hair bundle with BAPTA or dihydrostreptomycin, which are known to impair transduction function (Assad et al., 1991; Kroese et al., 1989), rectification of the motile response disappeared.
外毛细胞（OHC）快速的电运动性依赖于电压，并由OHC跨膜电位的变化驱动。这些变化包括由机械电换能器可变电导产生的感受器电位（埃文斯和达洛斯，1993年）。在本文所述的实验中，我们表明机械电换能器的电压依赖性会影响OHC对外部电场的低频运动反应。将OHC完全插入玻璃吸管（微腔）中，使得只有角质板和毛束暴露于浴液中。使用该技术，当微腔内的指令电压使顶端膜去极化时，观察到机械反应的整流，这相当于毛束的兴奋性位移。当OHC电压门控电导被阻断时，反应的形状持续存在。在用已知会损害转导功能的BAPTA或二氢链霉素处理毛束后（阿萨德等人，1991年；克罗泽等人，1989年），运动反应的整流消失。
