OCULOMOTOR SYSTEM-NEURAL STRUCTURE AND FUNCTION

描述(摘自申请者的摘要)：前庭眼球反射 (VOR)对正常视觉是必不可少的，因为它减少了图像在 头部运动时的视网膜。VOR患者的视觉功能 视力模糊和复视会严重损害视力障碍。虽然临床上 半规管功能障碍的测试是可用的，但没有标准 耳石功能障碍和线性VOR缺乏症的临床测试。 平移头部运动的眼睛补偿(线性VOR)更多 比头部旋转运动补偿更复杂的神经生理学 人们对此的了解要少得多。对于线性VOR，方向和幅度 代偿性眼动取决于凝视方向、观看距离和 头部的直线运动。与角度VOR不同的是，没有固定的 前庭血流量与运动输出的关系。情结 线性VOR与凝视的关系表明，这是一种行为 在反射性和自愿性之间。这项提议的目的是澄清 凝视信息与耳石相互作用的神经生理学基础 作为眼外运动指令产生基础的传入信号 用于线性VOR的肌肉。 为了实现这一目标，我们将使用单一单元记录来量化 分析编码直线运动和眼动变量的中央信号 非人灵长类动物。我们将对两个假设进行严格评估。假设1： 前庭神经元在同一方向上编码眼睛和头部的速度 (眼头神经元)是线性VOR通路的重要组成部分。眼头 神经元将展示与单眼运动相关的活动和编码 视线调制的头部直线运动信号。假设2)浦肯野细胞， 位于小脑小叶/腹侧小叶旁将编码 视线调制的头部直线运动信号。在这两个结构中，神经元将 根据眼球运动方向和眼球选择性进行组织。我们 将从行为上识别细胞，并确定它们与 周围迷路和/或小脑使用电微刺激。 我们的目标是确定这些细胞网络如何改变前庭 与耳石有关的传入信号和中央眼球运动信号 凝视眼球运动指令。

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.