OLIVOCOCHLEAR EFFERENT SYSTEMS

描述（研究者摘要）：研究者提出了一系列 测量，以解决许多理论上重要的问题， 在完整的耳蜗中使用内侧的作用， 橄榄耳蜗传出神经作为工具。 一个次要的目标是了解 在听觉神经中由传出神经产生的刺激编码的变化。 所获得的数据应提供与这些问题相关的重要新见解。 问题是：什么事件控制着神经纤维的放电？ 传出活动是否部分通过耳蜗内的变化起作用 潜力？ 哪些因素使高血压患者的神经纤维的反应 自发放电率与低自发放电率的不同？ 传出神经引起了哪些神经纤维放电的变化 当声音远高于阈值且不在纤维处时的活动 特征频率（CF）？ 双音抑制是如何产生的， 它是如何受到传出活动的影响的？ 耳声发射 产生的，以及传出活动如何影响它们？ 时间怎么过 各种传出效应的过程相互关联，并与 引起这些效应的潜在传出行为？ 多大 是单个传出纤维对神经反应的影响， 这些影响如何叠加？ 研究人员将通过以下方式解决这些问题：1.比较 不同SIRS对听神经纤维的传出诱发效应，但 来自同一只猫的相同CF，2：测量机械和神经 双音抑制效应，并将这些效应与 传出刺激 3：测量内侧传出神经的时程 影响（机械，电气和神经）的冲击， 和4. 确定媒体数量之间的对应关系， 火的作用和产生的效果。 耳蜗变化 力学将通过测量刺激频率的变化来监测 发射和传出诱发的电变化将被监测， 测量耳蜗内电位的变化。

DESCRIPTION (Investigator's Abstract): The investigators propose a series of measurements to address many theoretically important issues at the level of cellular interactions in the intact cochlea using the action of medial olivocochlear efferents as a tool. A subsidiary goal is to understand the changes produced by efferents in stimulus coding in the auditory nerve. The data obtained should provide significant new insights relevant to such questions as: What events control the firing of auditory-nerve fibers? Does efferent activity act in part through a change in endocochlear potential? What factors make responses of auditory-nerve fibers with high spontaneous firing rates different from those with low spontaneous rates? What changes in firings of auditory-nerve fibers are produced by efferent activity when sounds are well above threshold and not at the fiber characteristic frequency (CF)? How is two-tone suppression produced, and how is it influenced by efferent activity? How are otacoustic emissions generated, and how does efferent activity affect them? How do the time courses of various efferent effects relate to one another and to the underlying efferent actions which give rise to these effects? How large are the effects of a single efferent fiber on auditory-nerve responses, and how do these effects summate? The investigators will address these questions by 1: comparing efferent-evoked effects on auditory-nerve fibers with different Sirs but the same CF from the same cat, 2: measuring both mechanical and neural effect of two-tone suppression and comparing these effects with those efferent stimulation. 3: measuring the time courses of medial-efferent effects (mechanical, electrical and neural) in response to trains of shock, and 4. determining the correspondence between the number of medial efferents that fire and the effects produced. Changes in cochlear mechanics will be monitored by measuring changes in stimulus frequency emissions and efferent-evoked electrical changes will be monitored by measuring changes in endocochlear potential.