Peripheral vestibular hypofunction and neurosensory coding

项目摘要 拟议的研究解决了有关翻译重要性高的关键问题， 前庭感觉上皮部分功能障碍的机制和结果，称为外周 前庭功能减退该研究计划利用化学毒素诱导的功能减退， 通过PI实验室最近在动物模型中的工作， 外淋巴内给药导致产生高度可再现的损伤。这为以下方面提供了基础： 在感觉神经上皮内产生分级程度的损伤，通过 组织病理学分析。这些病变的生理结局将通过记录 单个传入神经元电生理和前庭眼反射，为建立 组织学和生理学与前庭功能的直接行为测试相关。先前的工作已经 表明传入神经元萼是高度不稳定的病理妥协，并由于其 重要的贡献，塑造神经动力学在未经治疗的上皮细胞，它是一个重点，评估病理 损害目前的研究计划将使传入放电动力学的直接相关的关键 花萼的细胞成分，包括其形态和KCNQ 4和钠-钾的表达 ATP酶此外，我们还将研究受损上皮毛细胞内突触带的分布， 测试系统性突触病是否也会导致前庭功能受损。在 总之，目前的研究提供了重要的洞察到前庭的组织病理学基础， 功能减退和感觉编码的改变是功能损害的基础。与此同时， 然而，这项研究将揭示正常发育所需的重要细胞和生理指标， 前庭功能，解决前庭神经生物学中长期存在的问题。

Project Summary The proposed research addresses critical issues of high translational importance concerning the mechanisms and outcomes of partial dysfunction of the vestibular sensory epithelia, referred to as peripheral vestibular hypofunction. The research plan utilizes chemotoxin- induced hypofunction, the foundation for which was identified through recent work from the PI’s laboratory in an animal model enabling precise intraperilymphatic dosing resulting in the production of highly reproducible lesions. This provides the basis for producing lesions of graded magnitudes within the sensory neuroepithelia, documented through histopathologic analyses. The physiologic outcome of these lesions will be evaluated through recordings of single afferent neuron electrophysiology and the vestibulo-ocular reflex, providing the bases for establishing histologic and physiologic correlates to a direct behavioral test of vestibular function. Previous work has demonstrated that the afferent neuron calyx is highly labile to pathologic compromise, and owing to its important contribution to shaping neural dynamics in untreated epithelia it is a focus for assessing pathologic damage. The present research plan will enable the direct correlate of afferent discharge dynamics to critical cellular components of the calyx, including its morphology and expression of KCNQ4 and sodium-potassium ATPase. In addition, we will examine the distribution of synaptic ribbons within hair cells of lesioned epithelia, testing whether a systematic synaptopathy also contributes to the compromised vestibular function. In summary, the present investigation provides critical insight into the histopathologic substrates of vestibular hypofunction and the alterations in sensory coding that underlies the functional compromise. At the same time, however, this investigation will reveal important cellular and physiologic metrics that are required for normal vestibular function, addressing longstanding question in vestibular neurobiology.