EFFERENT INFLUENCE--COCHLEAR MECHANOELECTRIC PHYSIOLOGY

传出影响--耳蜗机电生理学

• 批准号: 6150478
• 负责人: ALFRED L NUTTALL
• 金额: $ 47万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-04-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6150478
• 关键词: biomechanics; cell motility; cochlea; cochlear microphonic potentials; ear hair cell; efferent nerve; electrostimulus; guinea pigs; inferior colliculus; interferometry; mechanical stress; neurophysiology; neurotransmitters; nitric oxide; olivocochlear bundle

Sound stimulation of the cochlea leads to mechanoelectric activity in the organ of Corti. Outer hair cells play a central but little understood role in the normal cochlea response to sound. Furthermore, outer hair cell (OHC) activity is controlled in an almost completely unknown way by a complex innervation from the olivocochlear efferent fibers. This proposal seeks to add to our understanding of organ of Corti function by examining its mechanoelectric responses to sound and to efferent nerve electric stimulation. Organ of Corti responses will be measured as gross cochlear potentials, ear canal otoacoustic responses, receptor potentials of hair cells, and most importantly as velocity and displacement responses measured from various locations in the or an of Corti. Each of these measurements provides a different viewpoint on the performance of inner and OHCs acting together in vivo. This proposal applies a dramatic new technology for the study of cellular vibration in the inner ear. Laser feedback interferometry (LFI) is a method with sufficient sensitivity to register the vibration of nearly transparent cellular elements. LFI applied through a microscope allows one to focus a laser beam onto the different cellular structures in the organ of Corti. A detailed study of the traveling wave will provide an important empirical base for theoretical studies of organ of Corti function by providing information on mechanical displacements of its cellular structures. This understanding is necessary in order to determine how mechanical energy stimulates the inner and OHCs. LFI microscopy can provide the cellular displacement measurements needed to determine how OHCs serve as motile elements in this system. The proposal will also study the physiology of the olivocochlear efferent system and determine whether activation of the efferent nerves changes the mechanical properties of OHCs. The physiology of the descending efferent system from the inferior colliculus is included as a way to cause activation of both the medial and the lateral efferent systems in a topographic manned Finally, with this proposal we are beginning the study of the physiology of the supporting cells of the organ of Corti. Until recently supporting cells were thought to be largely passive elements only lending structural support to the system.There is mounting evidence now that Deiters' cells are motile and dynamic structures. We will measure the changes in organ of Corti vibration following types of stimulation that lead to changes in Deiters' cell morphology. Taken together the studies of this proposal will provide an understanding of: how OHCs generate high frequency selectivity and sensitivity in the normal inner ear; the function of the olivocochlear efferent system and the structural dynamics of supporting cells in the organ of Corti.

声音刺激耳蜗会导致耳蜗的机械电活动 柯蒂氏器。 外毛细胞发挥着核心作用，但人们对此知之甚少。 在正常耳蜗对声音的反应中发挥作用。此外，外毛细胞 (OHC) 活动以几乎完全未知的方式由 橄榄耳蜗传出纤维的复杂神经支配。这个提议 试图通过检查来增加我们对柯蒂函数器官的理解 它对声音和传出神经电的机电反应 刺激。柯蒂氏器反应将被测量为总耳蜗 电位、耳道耳声反应、毛发受体电位 细胞，最重要的是速度和位移响应 从柯蒂岛或柯蒂岛的不同位置测量。这些中的每一个 测量提供了关于内部性能的不同观点 和 OHC 在体内共同作用。 该提案应用了一项引人注目的新技术来研究细胞 内耳的振动。激光反馈干涉测量（LFI）是一种 具有足够灵敏度的方法来记录近乎的振动 透明的细胞元件。通过显微镜应用 LFI 可以使 将激光束聚焦到器官中的不同细胞结构上 柯蒂.对行波的详细研究将提供重要的 柯蒂函数器理论研究的经验基础 提供有关其细胞机械位移的信息 结构。为了确定如何 机械能刺激内在和OHC。 LFI 显微镜可以 提供确定如何进行所需的细胞位移测量 OHC 在该系统中充当运动元件。 该提案还将研究橄榄耳蜗传出神经的生理学 系统并确定传出神经的激活是否改变 OHC 的机械性能。下行传出神经的生理学 包括来自下丘的系统作为引起 激活内侧和外侧传出系统 地形载人 最后，根据这个建议，我们开始了生理学的研究 柯蒂氏器的支持细胞。直到最近还在支持 细胞被认为主要是被动元件，仅提供结构性作用 支持该系统。现在有越来越多的证据表明 Deiters 的细胞 是运动和动态的结构。我们将测量器官的变化 柯蒂振动遵循导致变化的刺激类型 Deiters 的细胞形态。 总的来说，对该提案的研究将提供一个理解 的：OHCs如何产生高频选择性和灵敏度 正常内耳；橄榄耳蜗传出系统的功能和 柯蒂氏器中支持细胞的结构动力学。