标题： 电压动力学对感觉毛细胞模型中反应特性的影响 显示英文标题

标题： Effect of voltage dynamics on response properties in a model of sensory hair cell

摘要： 听觉和前庭器官中的感觉毛细胞依赖于主动机制来实现高灵敏度和频率选择性。近期的实验研究表明，在低等脊椎动物的毛细胞中记录到两种不同水平上的自持振荡。首先，毛束可以自发地进行机械振荡；其次，观察到了毛细胞基底-外侧膜上的体电位振荡。我们开发了一个关于牛蛙囊状器官毛细胞的生物物理模型，该模型由机械和电学两个部分组成，用于研究机械振荡与电压振荡如何相互作用产生协调的自持振荡，以及这种相互作用如何影响毛细胞的整体灵敏度和选择性。该模型结合了非线性的随机毛束系统和描述体离子电流的 Hodgkin-Huxley 类型系统，并且双向耦合。我们隔离了模型参数空间中协调的自发振荡区域，然后研究了隔室之间的耦合如何影响毛细胞对外部机械扰动的敏感性。结果显示，自发的电振荡可能会显著提高毛细胞的灵敏度和选择性。 显示英文摘要

摘要： Sensory hair cells in auditory and vestibular organs rely on active mechanisms to achieve high sensitivity and frequency selectivity. Recent experimental studies have documented self-sustained oscillations in hair cells of lower vertebrates on two distinct levels. First, the hair bundle can undergo spontaneous mechanical oscillations. Second, somatic electric voltage oscillations across the baso-lateral membrane of the hair cell have been observed. We develop a biophysical model of the bullfrog's saccular hair cell consisting of two compartments, mechanical and electrical, to study how the mechanical and the voltage oscillations interact to produce coherent self-sustained oscillations and how this interaction contributes to the overall sensitivity and selectivity of the hair cell. The model incorporates nonlinear mechanical stochastic hair bundle system coupled bi-directionally to a Hodgkin-Huxley type system describing somatic ionic currents. We isolate regions of coherent spontaneous oscillations in the parameter space of the model and then study how coupling between compartments affect sensitivity of the hair cell to external mechanical perturbations. We show that spontaneous electrical oscillations may enhance significantly the sensitivity and selectivity of the hair cell.