IN VITRO STUDIES OF COCHLEAR NEUROBIOLOGY

根据普遍的共识，外毛细胞（OHC）是细胞的关键细胞。 哺乳动物耳蜗处理声音的能力具有高灵敏度， 在很宽的频率范围内具有高的频率分辨率。OHC赤字， 由环境损害、疾病或老化过程引起， 听力损失的主要原因是什么？等 损失可能影响多达2000万美国人。当地的存在 哺乳动物耳蜗内的机械反馈现在被广泛接受。在 内毛细胞（IHC）是真正的感觉受体， 耳朵，并将听觉信息传递到中枢神经系统。在 相比之下，外毛细胞（OHC）被认为没有显著的 （听觉）受体功能，但作为效应器（运动）元件的主要作用 在最终控制IHC输入的机械反馈回路中。 该反馈代表耳蜗放大过程。形状变化 OHC的运动性被认为是能量反馈的机制 到振动的耳蜗隔板。 提出了一系列实验来评估和量化各种运动性 分离的外毛细胞的特性。两者都是电诱导的 （电运动性）和诱导的纤毛移位（机械运动性） 研究了躯体形状变化反应。此外， 睫状束反应性，与膜电位变化有关， 检查躯体运动反应。技术开发在我们的 实验室允许在模拟体内进行这些测量 环境中，在纳米分辨率，并超过和超过充分 音频带宽。这些研究的目的是阐明 细胞和纤毛运动的生物物理学作为可能的基础， 耳蜗放大器，并了解OHC功能。

By common consensus, outer hair cells (OHCs) are the key requisites of the mammalian cochlea's ability to process sound with high sensitivity and exquisite frequency resolution over a wide frequency range. OHC deficit, arising from environmental insults, disease or from the aging process, tends to be the initial cause of most sensorineural hearing loss. Such loss may affect as many as 20 million Americans. The existence of local mechanical feedback within the mammalian cochlea is now well accepted. In this scheme inner hair cells (IHC) are the true sensory receptors of the ear and, transmit auditory information to the central nervous system. In contrast, outer hair cells (OHC) are assumed not to have significant (auditory) receptor function but a major role as effector (motor) elements in a mechanical feedback loop which ultimately controls the input to IHCs. This feedback represents the cochlear amplification process. Shape changes (motility) of OHCs are assumed to be mechanism whereby energy is fed back to the vibrating cochlear partition. An array of experiments is proposed to assess and quantify various motile properties of isolated outer hair cells. Both electrically induced (electromotility) and ciliary displacement induced (mechanomotility) somatic shape change responses are studied. In addition, alterations in ciliary bundle responsiveness, related to membrane potential changes and somatic motile responses, are examined. Techniques developed in our Laboratory permit these measurements to he made in a simulated in vivo environment, at nanometer resolution, and over and exceeding the full audio bandwidth. The purpose of these studies is to elucidate the biophysics of cellular and ciliary motility as possible bases of the cochlear amplifier and to understand OHC function.