ACTIVE FILTERING IN THE COCHLEA

最近的实验证据表明，外毛细胞的 哺乳动物的耳蜗充当机电放大器， 听觉灵敏度提高一百倍 拟议的长期目标 研究是为了证实这一假设，并澄清我们的理解 潜在的机制。 这项建议的具体目的是为了获得 实验证据支持一个详细的假设描述 耳蜗放大器的功能。 我们的假设是， 外毛细胞受体电流调节力产生过程， 位于毛细胞静纤毛中。 这个力与 基底膜和顶盖膜并显着增加机械强度 刺激内毛细胞。 我们计划通过注入以下资源来促进部队组建进程： 电流进入耳蜗的中阶，并测量 所产生的机械响应为鼓膜处的耳声发射 膜的 我们还将使用声学刺激并测量耳蜗 微音器研究外毛细胞受体电流的作用。 我们 将研究实验操作的影响， 放大过程 耳蜗刺激的效果 还将研究对部队生成过程的影响。 所提出的实验的结果以及先前的实验， 我们自己和其他人将被解释的援助计算 模型 计算模型是基于物理的，包括特定的 描述基底膜和盖膜的特性， 以及毛细胞的转导过程。

Recent experimental evidence suggests that the outer hair cells of the mammalian cochlea act as electromechanical amplifiers which increase hearing sensitivity one-hundred-fold. The long term goal of the proposed research is to confirm this hypothesis and to clarify our understanding of the underlying mechanisms. The specific aim of this proposal is to obtain experimental evidence in support of a detailed hypothesis describing the function of the cochlear amplifier. Our specific hypothesis is that the outer hair cell receptor current regulates a force-generation process which is located in the hair cell stereocilia. This force is coupled to the basilar and tectorial membranes and significantly increases the mechanical stimulus to the inner hair cells. We plan to stimulate the force-generation process through the injection of electrical current into scala media of the cochlea and to measure the resulting mechanical response as an otacoustic emission at the tympanic membrane. We will also use acoustic stimulation and measure the cochlear microphonic to study the role of the outer hair cell receptor current. We will study the effects of experimental manipulations which modify the amplification process. The effects of stimulation of the cochlear efferents on the force-generation process will also be studied. The results of the proposed experiments as well as previous experiments by ourselves and others will be interpreted with the aid of computational models. The computational models are physically based and include specific descriptions of the properties of the basilar and tectorial membranes as well as the hair cell transduction processes.