IN VIVO ANALYSIS OF OUTER HAIR CELL MOTILITY

外毛细胞活力的体内分析

• 批准号: 3218536
• 负责人: JOSEPH R SANTOS-SACCHI
• 金额: $ 13.28万
• 依托单位: YALE 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 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3218536
• 关键词: basolateral membrane; cell motility; dielectric property; ear hair cell; electrical potential; evoked potentials; gap junctions; guinea pigs; hypoxia; neural information processing; neurophysiology; single cell analysis

During the last decade, many characteristics of OHC motility have been garnered through the in vitro (isolated cell) approach, including voltage dependence, subcellular site, nonlinearity, sensitivity, and phase. Despite such progress, it remains a difficult task to envision exactly how OHC motility might induce sharp tuning in the basilar membrane (BM), IHCs and single units. It is entirely possible that characteristics of OHC motility observed in vitro may differ from those within the normal in vivo milieu. A determination of in vivo characteristics in requisite for an accurate assessment of the influence of OHC motility on BM mechanics. OHC motility in contributing something special to peripheral auditory processing, but exactly what and how remain key questions which certainly require in vivo investigations. In this regard, it in proposed to analyze aspects of OHC motility in the intact cochlea. 1) Is it possible to measure the effects of the electrically evoked motility of a single OHC on basilar membrane notion? The in vivo measurement of BM motion during current injection in a single OHC may unequivocally demonstrate that OHC can influence the BH, and may permit the determination of the in vivo voltage-to-movement (V-M) function. 2) What in the voltage dependence of OHC nonlinear capacitance in vivo? OHCs possess a voltage dependent capacitance. Measures of nonlinear capacitance will provide insight into the voltage dependence of OHC motility in vivo, and should compliment data on the in vivo V-M function. 3) Does transient hypoxia alter the voltage dependence of the in vivo motility and nonlinear capacitance functions? It is clear that metabolic insult in vivo can dramatically and reversibly interfere with the normal functioning of the organ of Corti. A concomitant change in these OHC characteristics may provide evidence for OHC motility involvement. 4) Are OHCs coupled via gap junctions to supporting calls? A sensitive capacitive technique will be used to confirm the results of Zwislocki et al., which indicate that coupling exists. Communication between these cell types may provide an interesting mechanism for controlling OHC function. In sum, this type of in vivo analysis may help to understand how the OHC performs its duties, and further, may provide insight into the auditory pathologies which have as their basis OHC dysfunction.

在过去的十年中，OHC 动力的许多特征已被 通过体外（分离细胞）方法获得，包括电压 依赖性、亚细胞位点、非线性、敏感性和相位。 尽管取得了这些进展，但准确地设想仍然是一项艰巨的任务 OHC 运动如何引起基底膜 (BM) 的急剧调节， IHC 和单一单位。其特征完全有可能是 体外观察到的 OHC 运动可能与正常情况下的不同 体内环境。 确定必要的体内特性 准确评估 OHC 运动对 BM 的影响 机械师。 OHC 为外周贡献一些特殊的东西的动力 听觉处理，但究竟什么以及如何处理仍然是关键问题 当然需要体内研究。 对此，建议 分析完整耳蜗中 OHC 运动的各个方面。 1) 是否可以测量电诱发的影响 单个 OHC 对基底膜概念的运动？体内 在单个 OHC 中电流注入期间测量 BM 运动可以 明确证明 OHC 可以影响 BH，并可能允许 体内电压-运动 (V-M) 函数的测定。 2）OHC体内非线性电容的电压依赖性如何？ OHC 具有电压依赖性电容。 非线性测量 电容将有助于深入了解 OHC 的电压依赖性 体内运动性，并且应该补充体内 V-M 功能的数据。 3）短暂缺氧是否会改变体内电压依赖性 运动性和非线性电容函数？很明显，代谢 体内损伤会显着地、可逆地干扰正常的 柯蒂氏器的功能。 这些 OHC 随之发生变化 特征可能为 OHC 运动参与提供证据。 4) OHC 是否通过间隙连接耦合到支持呼叫？一个敏感的 电容技术将用于确认 Zwislocki 等人的结果 等，这表明耦合存在。 这些之间的通信 细胞类型可能为控制 OHC 提供一种有趣的机制 功能。 总之，这种类型的体内分析可能有助于了解 OHC 如何 履行其职责，并且进一步可以提供对听觉的洞察 以 OHC 功能障碍为基础的病理学。