CELLULAR MECHANISMS OF THE VESTIBULAR SYSTEM

前庭系统的细胞机制

• 批准号: 6030188
• 负责人: JAY M GOLDBERG
• 金额: $ 37.95万
• 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 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6030188
• 关键词: Chelonia; acetylcholine; action potentials; adenosine; adenosine triphosphate; afferent nerve; calcitonin gene related peptide; ear hair cell; gamma aminobutyrate; glutamates; neural transmission; neuronal transport; neuropharmacology; potassium channel; potassium ion; synapses; vestibular nerve; voltage /patch clamp

The long-term goal of this work is to understand how vestibular organs work. The proper function of these organs is crucial to a healthy existence; damage can lead to debilitating vertigo, dizziness and inability to maintain study gaze. Mamammal, birds and reptiles have similar vestibular organs, with two classes of sensory receptor cell, the type I and type II hair cells. These cells transduce head movements into electrochemical signals that are transmitted across synapses to the terminals of afferent nerve fibers, which convey the signals to the brain in the form of electrical discharges. Efferent nerve fibers from the brain make synapses on h air cells and afferent nerve terminals, through which they influence afferent signals by unknown mechanisms. The specific aims are to characterize: 1) afferent synaptic transmission from the hair cells to the neurons; 2) the cellular mechanisms responsible for discharge regularity and maximum evoked discharge rates of afferent neurons; 3) efferent actions. In vitro preparations of the posterior semicircular canal organ of the turtle will be used. This organ lends itself to comparison of type I and type II hair cells, shows richly diverse efferent actions on afferent nerve fiber discharges, and is robust in vitro. Depending on the specific experiment, stimuli will be mechanical (displacement of the canal fluid), manipulations of membrane voltage or current in hair cells or afferent neurons, or electrical stimulation of efferent nerve fibers. The membrane voltage or current responses of hair cells and afferent neurons to these stimuli will be recorded intra cellularly with sharp micropipettes or patch pipettes. Both conventional (vesicular, orthograde) and unusual forms of transmission between the type I hair cell and afferent neuron will be characterized. Whether afferent discharge regularity is due to presynaptic (hair cell) or postsynaptic (afferent neuron) mechanisms will be tested. whether stages following mechanoelectrical traduction determine saturation of afferent discharge rates will be investigated. Efferent-evoked synaptic potentials and the neurotransmitter receptors responsible will be characterized.

这项工作的长期目标是了解前庭 器官工作。 这些器官的正确功能对 健康的存在；损坏会导致眩晕， 头晕和无法保持研究目光。 mamammal，鸟 和爬行动物具有类似的前庭器官，有两类 感觉受体细胞，I型和II型毛细胞。 这些细胞 将头部运动转移到电化学信号中 跨突触传播到传入神经的末端 纤维，将信号传达给大脑的形式 电气放电。 大脑的传出神经纤维使 通过H空气电池和传入神经末端的突触 它们通过未知机制影响传入信号。 具体目的是表征：1）传入突触 从毛细胞传播到神经元； 2）细胞 负责排放规律性和最大的机制 诱发传入神经元的排出率； 3）传出动作。 在 体外制剂的后半圆形管 乌龟将被使用。 这个器官适合I型的比较 和II型毛细胞，在对 传入的神经纤维排出，体外稳健。 取决于 在特定的实验上，刺激将是机械的 （移位管流体），膜的操作 毛细胞或传入神经元中的电压或电流，或电气 刺激传出神经纤维。 膜电压或 毛细胞和传入神经元的当前反应 刺激将用尖锐的微孔记录在细胞内 或补丁管。 都是常规（囊泡，矫正）和 I型毛单元与 传入神经元将被表征。 是否流放 规律性是由于突触前（毛细胞）或突触后（传入） 神经元的机制将进行测试。 是否以下阶段 机械电气传统确定传入的饱和 排放率将进行研究。 传出诱发的突触 负责的电位和神经递质受体将是 特征。