The lipid bilayer plays a pivotal role in force transmission to many mechanically-gated channels. We developed the technology to monitor membrane diffusivity in order to test the hypothesis positing that Ca²⁺ regulates open probability (P_o) of cochlear hair cell mechanotransduction (MET) channels via the plasma membrane. The stereociliary membrane was more diffusive (9x) than the basolateral membrane. Elevating intracellular Ca²⁺ buffering or lowering extracellular Ca²⁺ reduced stereociliary diffusivity and increased MET P_o. In contrast, prolonged depolarization increased stereociliary diffusivity and reduced MET P_o. No comparable effects were noted for soma measurements. Although MET channels are located in the shorter stereocilia rows, both rows had similar baseline diffusivity and showed similar responses to Ca²⁺ manipulations and MET channel blocks, suggesting that diffusivity is independent of MET. Together, these data suggest that the stereociliary membrane is a component of a calcium-modulated viscoelastic-like element regulating hair cell mechanotransduction.

脂质双层在力传递到许多机械门控通道中起着关键作用。我们开发的技术来监测膜扩散以便测试该假说认为：放置的Ca ²⁺调节开放概率（P _ø通过质膜耳蜗毛细胞机械传导（MET）信道）。立体睫状膜比基底外侧膜扩散性更高（9倍）。升高细胞内Ca ^2+的缓冲作用或降低细胞外Ca ^{2+的作用会}降低立体纤毛扩散性并增加MET P _o。相反，长时间的去极化会增加睫状纤毛的扩散性并降低MET P _o。体格测量未发现可比的效果。尽管MET通道位于较短的立体睫毛行中，但两行的基线扩散率相似，并且对Ca ²⁺操作和MET通道阻滞显示相似的响应，这表明扩散率与MET无关。总之，这些数据表明，立体纤毛膜是调节毛细胞机械转导的钙调节粘弹性样元件的组成部分。