ACTIVE FILTERING IN THE COCHLEA

最近的实验证据表明，人的外毛细胞 哺乳动物的耳蜗作为机电放大器，增加了 听力敏感度提高了一百倍。建议的长期目标是 研究是为了证实这一假设，并澄清我们对 潜在的机制。这项提议的具体目的是获得 支持详细假说的实验证据 耳蜗功放的功能。我们的具体假设是 外毛细胞感受器电流调节力的产生过程， 位于毛细胞内的立体纤毛。这一力耦合到 基底膜和覆盖膜，并显著增加机械 刺激内毛细胞。 我们计划通过注入以下物质来刺激力量的产生过程 电流进入耳蜗骨中阶，测量耳蜗骨中段电流 在鼓室产生的作为耳声发射的机械反应 薄膜。我们还将使用声刺激和测量耳蜗值 麦克风研究外毛细胞感受器电流的作用。我们 将研究实验操作的效果，这些操作改变了 放大过程。刺激耳蜗术后的影响 还将研究力产生过程中的传出因素。 建议的实验结果以及之前的实验结果由 我们自己和其他人将在计算的帮助下被解释 模特们。计算模型是以物理为基础的，包括特定的 基底膜和覆盖膜的特性描述为 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.