OLIVOCOCHLEAR EFFERENT SYSTEMS AND COCHLEAR PHYSIOLOGY

描述：(改编自申请者摘要)：尽管在 了解耳蜗功能的多个方面，在关键领域的知识 耳蜗细观力学是尖端宏观力学的基础和知识 几乎是缺席的。在传统的观点中，基底膜运动弯曲。 内毛细胞(IHC)立体纤毛通过单一的振动模式 沿着基底膜的单一行波。然而，这一观点并不 与我们最近的工作相吻合，它表明有多个励磁驱动器或 机械和神经数据显示顶端有多组延迟。 有几条证据表明了耳蜗细观力学的一个新概念 其中科尔蒂的管风琴以各种模式振动，每个模式都有自己的共鸣 频率，每一个都为IHC立体纤毛提供激励驱动。与 允许耳蜗区在多个重叠的运动中移动，可以 是多个行波。单根听神经纤维的录音 揭示多重共振，非常适合跟踪这些 沿着耳蜗线的共鸣。 拟议的工作将(1)区分影响 单个听神经纤维的反应，沿着耳蜗标绘它们，以及 确定它们的行波速度，(2)确定这些共振如何 受传出刺激和低频“偏见”音调的影响，以及(3) 测试一种假设，即一种深刻的耳蜗非线性控制着 某些模式之间的转换。 拟议的实验将检验我们初步提出的假设 结果出现了两个重叠的行波。我们的结果将 提供数据，以充实耳蜗力学的新图景 为形成新的实验和新的实验提供丰富的数据来源 耳蜗的生物物理学和细胞生物学基础模型 共鸣。由于听觉神经纤维实验不会侵入耳蜗组织， 我们对共振模式的描述存在于一个完整的， 正常运作的耳蜗会提供一个黄金标准，可以用来 确定所见模式和任何侵入性实验的正常情况。获取 在这个关键的机械层面上的整体功能特征是 对于理解外毛细胞的运动性和其他细胞 而耳蜗管的结构特性产生了耳蜗管的放大和导联 到耳蜗管的输出。

DESCRIPTION: (Adapted from applicant's abstract): Despite great progress in understanding many aspects of cochlear function, knowledge in the key area of cochlear micromechanics is rudimentary and knowledge of apical macromechanics is almost absent. In the conventional view, basilar-membrane motion bends inner-hair-cell (IHC) stereocilia by a single vibrational pattern and there is a single traveling wave along the basilar-membrane. However, this view does not fit with our recent work which shows there are multiple excitation drives or with mechanical and neural data showing multiple group delays in the apex. Several lines of evidence point to a new conception of cochlear micromechanics in which the organ of Corti vibrates in modes, each with its own resonant frequency and each providing an excitation drive to IHC stereocilia. With the cochlear partition allowed to move in multiple, overlapping motions, there can be multiple traveling waves. Recordings from single auditory-nerve fibers reveal the multiple resonances and are ideally suited for tracking these resonances along the cochlea. The proposed work will (1) distinguish the excitation drives that affects the responses of individual auditory-nerve fibers, map them along the cochlea, and determine their traveling wave velocities, (2) determine how these resonances are affected by efferent stimulation and low-frequency "bias" tones, and (3) test the hypothesis that a profound cochlear nonlinearity control the transition between certain modes. The proposed experiments will test the hypothesis suggested by our preliminary results that there ate two overlapping traveling waves. Our results will provide data that will flesh out a new picture of cochlear mechanics and provide a rich source of data for the formation of new experiments, and new models for the biophysical and cell-biological basis of the cochlear resonances. Since auditory-nerve-fiber experiment do not invade the cochlea, our characterization of the resonant modes present in an intact, normally-functioning cochlea will provide a gold standard that can be used to determine the normally of the modes seen and any invasive experiment. Obtaining an overall functional characterization at this pivotal mechanical level is essential for understanding how outer -hair-cell motility and other cellular and structure properties of the cochlea produce the cochlear amplifier and lead to output of the cochlea.