CELLULAR MECHANISMS OF THE VESTIBULAR SYSTEM

前庭系统的细胞机制

• 批准号: 3218582
• 负责人: JAY M GOLDBERG
• 金额: $ 19.96万
• 依托单位: UNIVERSITY OF CHICAGO
• 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/3218582
• 关键词: Chelonia; acetylcholine; afferent nerve; atropine; calcium flux; curare; ear hair cell; efferent nerve; electrical potential; electrophysiology; electrostimulus; head movements; innervation; membrane channels; neural conduction; neural transmission; neuroanatomy; neuropharmacology; neurophysiology; semicircular duct; tissue /cell culture; vestibular nerve; voltage /patch clamp

Our long-term goal is to understand the cellular mechanisms determining the discharge properties of vestibular-nerve afferents. To this end, an in vitro preparation of the turtle posterior crista has been developed. Its advantages are: 1) Afferent discharge properties are indistinguishable in the in vitro preparation and in intact, respiring animals. 2) Type I hair cells are restricted to a central zone, they make up the large majority of hair cells in this zone, and they are innervated by afferents having distinctive physiological properties. In a similar vein, bouton afferents differing in their physiological properties innervate distinct parts of the peripheral zone. Hence, by studying hair cells harvested from the different regions, it should be possible to correlate the physiology of hair cells and of the afferents innervating them. 3) Electrical stimulation of efferents produces excitation in some afferents and inhibition in others. Since the two kinds of afferents innervate distinct parts of the neuroepithelium, a study of hair cells drawn from specific regions should allow us to determine the cellular basis for both kinds of efferent actions. 4) Hair cells from this organ are relatively easy to isolate and to characterize with whole-cell tight-seal recordings. There are three specific aims: 1) To complete studies of vestibular- nerve discharge in the in vitro preparation. Afferents are characterized in terms of their responses to head rotations, their responses to electrical stimulation of efferent fibers, and the location and morphology of their peripheral terminations. 2) To characterize type I and type II hair cells, isolated from specific regions of the neuroepithelium, in terms of their voltage- and ion-sensitive currents, as well as the current evoked by the efferent transmitter, acetylcholine (ACh). 3) To extend the studies to the utricular macula of the turtle because this end organ offers advantages for some of the research planned for the next several years. The proposed studies are intended to contribute to two questions. What are the distinctive functions of type I hair cells and their calyx endings? What is the function of the efferent regulation of the vestibular end organs? The questions are of importance in understanding the operation of the vestibular labyrinth in health and disease.

我们的长期目标是了解确定的细胞机制 前庭神经传入的排放特性。 为此， 已经开发了乌龟后Crista的体外制备。 它的优点是：1）传入的放电属性是 在体外制剂中无法区分，完整，呼吸 动物。 2）I型毛细胞仅限于中央区域，它们 构成了该区域中绝大多数毛细胞，它们是 由具有独特生理特性的传入所支配。 在 类似的静脉，Bouton的传入与其生理不同 性质支配周围区域的不同部分。 因此，由 研究从不同区域收获的毛细胞，应该是 可以关联毛细胞和传入的生理学 支配它们。 3）产生传出的电刺激会产生 在某些传入中激发并抑制另一些。 从两者开始 一种神经上皮的不同部分的一种传入，一个 从特定区域绘制的毛细胞的研究应该使我们能够 确定两种传出作用的细胞基础。 4）头发 来自该器官的细胞相对易于分离和表征 带有全细胞紧密录音。 有三个特定的目的：1）完成前庭研究 在体外制剂中的神经排出。 传入是特征的 就他们对头部旋转的反应而言，它们对 发出纤维的电刺激，位置和 其外围终止的形态。 2）表征I型 和II型毛细胞，与特定区域分离 神经上皮，就其电压和离子敏感电流而言， 以及由传出发射器乙酰胆碱引起的电流 （ach）。 3）将研究扩展到乌龟的乌蒂尔黄斑 因为这个最终器官为计划的一些研究提供了优势 在接下来的几年中。 拟议的研究旨在提出两个问题。 什么 是I型毛细胞及其花萼的独特功能 结局？ 辐射调节的功能是什么 前庭端器官？ 这些问题对于理解很重要 前庭迷宫在健康和疾病中的操作。