IN VIVO ANALYSIS OF OUTER HAIR CELL MOTILITY

在过去的十年中，OHC运动的许多特征已经被发现， 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、灵敏度和相位。 尽管取得了这些进展， OHC运动性如何在基底膜（BM）中诱导急剧调谐， IHC和单个单位。完全有可能是 在体外观察到的OHC运动可能不同于正常的OHC运动。 体内环境。 测定所需的体内特性 为了准确评估OHC运动对BM的影响， 力学 OHC能动性在外周血中的作用 听觉处理，但究竟是什么和如何仍然是关键问题， 当然需要在体内进行研究。 在这方面，它建议 分析完整耳蜗中OHC运动的各个方面。 1)有没有可能测量电诱发的 基底膜上单个OHC的运动性概念？体内 在单个OHC中的电流注入期间测量BM运动可以 明确表明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)体内OHC非线性电容的电压依赖性如何？ OHC具有依赖于电压的电容。 非线性测度 电容将提供洞察OHC的电压依赖性 在体内的运动性，并应补充在体内V-M功能的数据。 3)短暂缺氧是否改变了体内的电压依赖性 运动和非线性电容功能？很明显，代谢 体内损伤可显著且可逆地干扰正常的 Corti器官的功能。 这些OHC的伴随变化 这些特征可能为OHC运动参与提供证据。 4)OHC是否通过间隙连接与支持性呼肠孤偶联？一个敏感 电容技术将被用来证实Zwislocki等的结果 例如，这表明存在耦合。 这些之间的沟通 细胞类型可能为控制OHC提供了一种有趣的机制 功能 总之，这种类型的体内分析可能有助于了解OHC是如何在体内发挥作用的。 履行其职责，并进一步，可以提供洞察听觉 以OHC功能障碍为基础的病理学。

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.