Sensory Coding Among Semicircular Canal Afferent Neurons

描述：（申请人提供） 本研究致力于阐明头部运动是如何 编码在初级传入神经元的放电特征中 支配前庭迷路的半规管嵴。其 另一个目的是显示这种神经代码是如何分布在 小脑皮质实验的目的是为了确定 宽带系统传递函数中反映的响应特性 并且在表征前庭传入感受野的新方法中， 分布在整个传入神经系统中。一 形态生理学策略将显示这些系统如何响应特征 映射到周围嵴神经上皮上。实验也 旨在确定传入的空间和时间编码是如何反映在 前庭传入苔藓纤维向腹侧悬雍垂的投射， 小脑皮质结节。这些研究的结果将阐明 半规管传入系统中感觉编码的基础， 解释传入生理多样性对 在小脑内处理。随后的地图也将提供桥梁 外周受体的研究和功能编码之间的联系， 传入神经元，这将提供一个功能背景， 毛细胞生理学和病理生理学研究解释 前庭周围病变的症状 在本研究中进行的实验利用 哺乳动物的电生理记录和细胞内标记方法 模型，以确定与以下各项相关的感觉编码的特征： 传入神经元的特定形态和生理特征。 将进行广泛的电生理记录，以阐明 传入反应动力学的连续体之间的传入合奏。这些是 在这些神经元的感受野模型的背景下进行分析， 这些个体传入对头部运动状态空间的区域进行编码。 传入响应动力学研究相对于轨迹 在嵴内的神经支配，并就其终止内 小脑悬雍垂和结节。这些实验将揭示新的见解 关于这种感觉中刺激编码的基本组织， 系统

DESCRIPTION:(provided by applicant) The present investigation is dedicated to elucidating how head movements are encoded in the discharge characteristics of primary afferent neurons innervating the semicircular canal cristae of the vestibular labyrinth. Its additional objective is to show how this neural code is distributed within the cerebellar cortex. The experiments are designed to determine how dynamic response characteristics, as reflected in broad-band systems transfer functions and in a novel approach to characterizing vestibular afferent receptive fields, are distributed with respect to the entire afferent ensemble. A morphophysiology strategy will show how these systems response characteristics are mapped onto the peripheral crista neuroepithelium. Experiments are also designed to determine how afferent spatial and temporal coding is reflected in the projections of vestibular afferent mossy fibers to the ventral uvula and nodulus of the cerebellar cortex. The results from these studies will elucidate the foundation of sensory coding in the semicircular canal afferent system, and the bases to interpret the contribution of afferent physiologic diversity to processing within the cerebellum. The ensuing maps will also provide the bridge between investigations of the peripheral receptor and the functional coding in the afferent neurons, which will provide a functional context with which to interpret studies of hair cell physiology and pathophysiologic investigations of peripheral vestibular lesions. The experiments to be conducted in this investigation utilize electrophysiologic recording and intracellular labeling methods in a mammalian model to identify the features of sensory coding that are associated with specific morphologic and physiologic characteristics of the afferent neuron. Extensive electrophysiologic recordings will be conducted to elucidate the continuum of afferent response dynamics among the afferent ensemble. These are analyzed in the context of a model of receptive fields for these neurons, in which individual afferents code for a region of head-movement state space. Afferent response dynamics are investigated with respect to the locus of innervation within the crista, and with respect to their terminations within the cerebellar uvula and nodulus. These experiments will reveal new insight regarding the fundamental organization of stimulus coding in this sensory system.