THE MECHANISM OF OUTER HAIR CELL MOTILITY

外毛细胞运动的机制

• 批准号: 6624803
• 负责人: RICHARD John HALLWORTH
• 金额: $ 20.08万
• 依托单位: CREIGHTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 2004-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6624803
• 关键词: biomechanics; cell motility; chemical kinetics; cochlea; ear hair cell; electrical conductance; electrical potential; electrophysiology; gerbil /jird; single cell analysis; sound frequency

DESCRIPTION: (Adapted from the Investigator's Abstract) The outer hair cell (OHC) of the mammalian cochlea, a sensory receptor cell, generates force when electrically stimulated. OHC force, driven in vivo by the acoustic receptor potential, is thought to contribute an extra step of mechanical excitation (the "cochlear amplifier") that improves tuning and is vulnerable to disease and insult. Recent experiments in this laboratory have shown that the axial stiffness of the OHC is essential to connect the OHC voltage-dependent motor to its load, the organ of Corti. But nothing is known about OHC stiffness at relevant acoustic frequencies nor are the cellular components underlying OHC stiffness understood. This proposal has three specific aims that will provide this information. In Aim1, OHC impedance (stiffness) will be measured directly at acoustic frequencies using a novel instrument, the laser stretcher. Whether membrane potential modulates impedance-a proposed mechanism of the cochlear amplifier-will be tested. The first direct measurement of isometric force will be made. In Aim 2, the role of OHC stiffness in the development of hearing will be determined, specifically whether the onset of OHC stiffness is a limiting event in development of the cochlear amplifer. In Aim 3, the role of the cortex, a subcellular structure in OHC stiffness will be determined using a developmental approach.

描述：（根据调查员的摘要改编）外毛细胞 哺乳动物耳蜗（一种感觉受体细胞）的（OHC）会产生力 电刺激。 OHC力，由声学受体在体内驱动 潜力被认为是机械激发的额外步骤（ “人工耳蜗放大器”），改进调整，容易受到疾病和疾病的影响 侮辱。该实验室的最新实验表明轴向 OHC的刚度对于将OHC电压依赖电机连接到 它的负载，Corti的器官。但是关于OHC刚度一无所知 相关的声频率也不是OHC基础的细胞成分 僵化。该提议具有三个具体目标，可以提供 此信息。在AIM1中，将直接测量OHC阻抗（刚度） 在声学频率下，使用新型仪器激光担架。无论 膜电势调节是阻抗A提出的人工耳蜗机制 放大器将测试。等距力的第一个直接测量将 被制作。在AIM 2中，OHC僵硬在听力发展中的作用将 确定，特别是OHC刚度的发作是有限的 人工耳蜗放大器开发的事件。在AIM 3中， 皮质，将使用A的OHC刚度中的亚细胞结构确定 发展方法。