Mechanisms of signaling in otoconial organs

项目摘要。正常的行为和空间定向依赖于来自内部的前庭信号。 耳朵前庭周围有两个主要的分支：半规管和耳锥器官。 前者已被深入研究。耳锥器官的了解要少得多，即使 对中枢前庭处理的研究越来越突出它们在控制姿势，注视， 空间定位和植物功能。因此，迫切需要了解这一重要的 迷宫的一部分。我们建议通过分析机械和生物物理来解决这一需求。 信号来源于一个主要的耳锥器官，椭圆囊。我们的实验准备是一只海龟， 用于分析外周听觉和前庭机制的首要模型系统。这 多学科的倡议分析了从行为到细胞建模的水平上的椭圆囊机制。它建立 根据我们目前对生物力学的研究结果，这些研究已经产生了最详细的数据基础， 椭圆囊的结构和力学，适用于任何脊椎动物。AIM1使用高速录像 和核磁共振图像的迷宫，以量化刺激，椭圆囊毛细胞暴露在自由 行为动物目标2和目标3将联合收割机实验力学与生物物理和计算力学相结合 分析以表征对这些刺激的重要机械和毛细胞反应。Aim 4用途 形态生理学，信息分析和建模，以量化所产生的传入信号及其 信息内容，将这些信号与毛细胞对相同刺激的反应进行对比，并测试假设 椭圆囊传入神经信号多样性的起源因此，建议的研究继续我们的努力 建立第一个详细的，定量的描述机制，形成椭圆囊信号的CMS。 本案无关前庭功能障碍是就诊的常见原因。它可能会让人特别残疾， 因此前庭缺陷是一个重要的医学、社会和经济问题。尽管它很重要， 前庭系统，特别是耳锥器官，远不如其他感觉器官了解得好。 系统.我们需要对耳石器官功能有新的认识，以提高诊断和治疗水平 战略布局通过对这一知识的贡献，拟议的研究与联合国的使命直接相关。 NIDCD。

Project summary. Normal behavior and spatial orientation depend upon vestibular signals from the inner ear. There are two major subdivisions of the vestibular periphery: semicircular canals and otoconial organs. The former have been intensively studied. Otoconial organs are much less well understood, even though studies of central vestibular processing increasingly highlight their importance in control of posture, gaze, spatial orientation, and vegetative functions. Thus, there is a pressing need to understand this important subdivision of the labyrinth. We propose to address this need by analyzing the mechanical and biophysical origins of signals from a major otoconial organ, the utricle. Our experimental preparation is a turtle, one of the premier model systems for analyses of peripheral auditory and vestibular mechanisms. This multidisciplinary initiative analyzes utricular mechanisms at levels from behavior to cellular modeling. It builds on results from our current studies of biomechanics, which have yielded the most detailed data base on the structure and mechanics of the utricle available for any vertebrate. Aim 1 uses high-speed video recording and NMR images of the labyrinth to quantify the stimuli that utricular hair cells are exposed to in freely behaving animals. Aim 2 and Aim 3 combine experimental mechanics with biophysical and computational analyses to characterize important mechanical and hair cell responses to these stimuli. Aim 4 uses morphophysiology, information analysis, and modeling to quantify the resulting afferent signals and their information content, contrast these signals with hair cell responses to the same stimuli, and test hypotheses about the origins of signal diversity in utricular afferents. Thus, the proposed research continues our efforts to build the first detailed, quantitative description of the mechanisms that shape utricular signals to the CMS. Relevance. Vestibular dysfunction is a common cause of physician visits. It can be particularly disabling, and vestibular deficits are thus a significant medical, social, and financial concern. In spite of its importance, the vestibular system, and otoconial organs in particular, are far less well understood than other sensory systems. We need new knowledge of otoconial organ function to improve diagnosis and treatment strategies. By contributing to this knowledge, the proposed research is directly relevant to the mission of the NIDCD.