OCULOMOTOR SYSTEM-NEURAL STRUCTURE AND FUNCTION

描述（改编自申请人摘要）：前庭眼反射 (VOR)对于正常视力是必不可少的，因为它减少了 头部运动时的视网膜。VOR患者的视觉功能 视力障碍严重受损，视力模糊和复视。尽管临床 半规管功能障碍的测试是可用的，没有标准 耳石功能障碍和线性VOR缺陷的临床试验。 头部平移运动的眼睛补偿（线性VOR）更多 复杂的比补偿旋转头部运动，其神经生理学 就不那么容易理解了对于线性VOR， 补偿性眼球运动的大小取决于注视方向、观看距离和 头部的直线运动不像有角度的VOR， 前庭流入和运动输出之间的关系。复杂 线性VOR与凝视的关系表明，它是一种行为， 反射性和自愿性之间的区别本提案的目的是阐明 注视信息与耳石相互作用的神经生理学基础 作为向眼外肌发出运动指令的基础的传入信号 线性VOR的肌肉。 为了实现这一目标，我们将使用单个单元记录来定量地 分析编码线性运动和眼动变量的中央信号， 非人类灵长类动物两个假设将被严格评估。假设1： 前庭神经元编码眼睛和头部在同一方向的速度 （眼-头神经元）是线性VOR通路的重要组成部分。眼头 神经元将表现出单眼眼球运动相关的活动， 凝视调制的线性头部运动信号。假设2）浦肯野细胞， 位于小脑绒球/腹侧绒球将编码 凝视调制的线性头部运动信号。在这两种结构中，神经元 根据眼动方向和眼的选择性来组织。我们 将从行为上识别细胞，并确定它们与 外周迷路和/或小脑使用电微刺激。 我们的目标是确定这些细胞的网络是如何将前庭神经元 来自耳石的传入信号和中央眼球运动信号， 凝视眼睛的指令

DESCRIPTION (Adapted from applicant's abstract): The vestibular ocular reflex (VOR) is essential for normal vision because it reduces image motion on the retina during head movements. The visual capability of patients with VOR disorders is severely impaired by blurred and double vision. Although clinical tests for semicircular canal dysfunction are available, there are no standard clinical tests for otolith dysfunction and linear VOR deficiencies. Ocular compensation of translational head movements (the linear VOR) is more complex than compensation for rotatory head movements, and its neurophysiology is much less well understood. For the linear VOR, the direction and amplitude of compensatory eye movement depends on gaze direction, viewing distance, and the linear motion of the head. Unlike the angular VOR, there is no fixed relationship between the vestibular inflow and the motor output. The complex relationship of the linear VOR to gaze suggests that it is a behavior somewhere between reflexive and voluntary. The goal of this proposal is to elucidate the neurophysiological basis for the interaction of gaze information with otolith afferent signals that underlies the generation of motor commands to extraocular muscles for the linear VOR. To accomplish this goal, we will use single unit recording to quantitatively analyze central signals encoding linear motion and oculomotor variables in non-human primates. Two hypotheses will be rigorously evaluated. Hypothesis 1: Vestibular neurons that encode eye and head velocity in the same direction (Eye-Head Neurons) are essential components in linear VOR pathways. Eye-Head neurons will exhibit monocular eye movement related activity and encode gaze-modulated linear head movement signals. Hypothesis 2) Purkinje cells, located in the cerebellar flocculus/ventral paraflocculus will encode gaze-modulated linear head movement signals. In both structures, neurons will be organized according to eye movement direction and ocular selectivity. We will identify cells behaviorally, and determine their connectivity with the peripheral labyrinth and/or the cerebellum using electrical microstimulation. Our goal is to determine how networks of these cells transform vestibular afferent signals from the otoliths and central eye movement signals related to gaze into oculomotor commands.