EFFERENT INFLUENCE ON COCHLEAR MECHANOELECTRIC PHYSIOLOG

描述：（改编自申请人的摘要。）该提案寻求 为了增加我们对Corti器官功能的了解， 机械电反应的声音使用四个不同的，但联系 测量方法;总耳蜗电位;耳道耳声 反应，细胞内毛细胞受体电位，和大多数 重要的是，基底膜运动。 每一个都提供了不同的 内毛细胞和外毛细胞的性能的观点。 首先将研究基底膜的详细运动模式， 使用新的方法来实现这一目的。 一个新的和详细的看法， 行波模式将为今后的研究提供重要的经验基础 Corti器官功能的理论模型，并建立一个点， 实验出发，以测量橄榄耳蜗传出活动。 自然的，声音诱发的，传出神经的激活以及电 将研究激活。 传出性中耳炎的耳道耳声变化 激活将直接与基底膜运动变化相比较。 这种比较将揭示一些机械方面的神经控制 外毛细胞性能。 传出系统的作用，以保护 OHC从响亮的声音的破坏性影响将被研究，以及将如何 传出活动可以提高我们检测和编码声音的能力， 存在掩蔽噪声。 研究人员还将研究高级脑干的生理学 下行传出通路的水平。 电流刺激 下丘区域的面积将用于激活该系统， 不仅为下行通路提供了新的信息， 也许还对未知的生理学的“横向”传出纤维 其终止于传入神经元的外周突起。

DESCRIPTION: (Adapted from the Applicants' Abstract.) This proposal seeks to add to our knowledge concerning organ of Corti function by examining its mechanoelectric responses to sound using four distinct, but linked measurement approaches; gross cochlear potentials, ear canal otoacoustic responses, intracellular hair cell receptor potentials, and most importantly, basilar membrane motion. Each of these provides a different viewpoint on the performance of inner and outer hair cells. The detailed motion pattern of the basilar membrane will be studied first, using a new method for this purpose. A new and detailed view of the traveling wave pattern will provide an important empirical base for future theoretical models of the organ of Corti function and establish a point of experimental departure to measure olivocochlear efferent activity. Natural, sound evoked, activation of efferents as well as electrical activation will be studied. Ear canal otoacoustic changes during efferent activation will be directly compared to basilar membrane motion changes. This comparison will reveal some mechanical aspects of neurally controlled outer hair cell performance. The role of the efferent system to protect OHCs from the damaging effects of loud sound will be studied, as will how efferent activity can improve our ability to detect and code sounds in the presence of masking noises. The investigators will also study the physiology of the higher brain stem levels of the descending efferent pathways. Electric current stimulation of areas of the inferior colliculus will be used to activate this system, leading not only to new information on the descending pathways proper but perhaps also on the unknown physiology of the "lateral" efferent fibers which terminate on the peripheral processes of afferent neurons.