OCULOMOTOR SYSTEM--NEURAL STRUCTURE AND FUNCTION

描述(PI摘要)：前庭眼反射(VOR)是 对正常视力至关重要，因为它能稳定视网膜上的图像 在正常的头部运动中。精神分裂症患者的视觉能力 影响VOR的障碍由模糊和双重严重损害 视力，以及视振荡。正常的头部运动包括角度和 翻译组件，这两个组件必须由 沃尔。角度VOR或Avor已经被很好地描述为 研究，但翻译VOR或TVOR只受到关注 最近。与Avor不同，Avor具有固定的响应幅度和 相对于旋转刺激的方向、幅度和方向 TVOR的大小取决于观察到的图像相对于每个 眼睛和头部的平移。这项提议的中心目标是 确定用于转化的神经生理机制 来自耳石的平移前庭传入信号 器官，转化为适当的代偿运动命令给 眼外肌。为了实现这一目标，我们将重点关注 灵长类前庭核团信号处理的两个方面：(1) 前庭和动眼神经信号处理的综合分析 在各种行为条件下的前庭核神经元 以及前庭刺激。这部分研究将侧重于动态 前庭信号的特征，耳石的会聚特性 以及前庭和眼睛之间的关系 由每个神经元编码的运动信号。(2)主要输出神经元 VOR是前庭次级神经元(目前称为PVP单位)。 和小叶靶神经元(FTN)。我们计划鉴定这些细胞 在行为上，通过电刺激迷路或 小脑小叶。在确认他们之后，我们将分析 这些细胞传递给运动神经元的命令信号，我们将 研究这些细胞如何将前庭和眼动输入转化为 运动指令适用于驱动动眼神经。我们会付钱的 特别注意分离的TVOR反应是如何通过 这些输出神经元。在进行这些研究时，我们将采用一种新的线性 Accutronics，Inc.根据我们的规格开发的滑板/旋转器 新仪器将使我们能够提供精确控制的线性(In 水平面)或(围绕偏航轴的)角刺激 与实验对象相结合。

DESCRIPTION (PI's abstract): The vestibular ocular reflex (VOR) is crucial for normal vision because it stabilizes images on the retina during normal head movements. The visual capability of patients with disorders affecting the VOR is severely impaired by blurred and double vision, and by oscillopsia. Normal head movements involve angular and translational components, both of which must be compensated for by the VOR. The angular VOR or AVOR has been well characterized by previous studies, but the translational VOR or TVOR has received attention only recently. Unlike the AVOR, which has a fixed response amplitude and direction relative to the rotatory stimulus, the amplitude and direction of the TVOR depends on the location of the viewed image relative to each eye and the head translation. The central goal of this proposal is to determine the neurophysiological mechanisms that are used to transform the translational vestibular afferent signal, derived from the otolith organs, into an appropriate compensatory motor command to the extraocular muscles. In order to accomplish this goal, we will focus on two aspects of signal processing in the primate's vestibular nucleus: (1) A comprehensive analysis of vestibular and oculomotor signal processing in vestibular nucleus neurons under a variety of behavioral conditions and vestibular stimuli. This part of the study will focus on dynamic characterization of vestibular signals, convergence properties of otolith and canal signals, and on the relationship between vestibular and eye movement signals encoded by each neuron. (2) The principal output neurons of the VOR are secondary vestibular neurons (currently called PVP units) and flocculus target neurons (FTNs). We plan to identify these cells behaviorally, and by electrical stimulation of the labyrinth or the cerebellar flocculus. After their identification, we will analyze the command signals delivered by these cells to motoneurons, and we will examine how these cells transform vestibular and eye movement inputs into the motor commands suitable to drive oculomotoneurons. We will pay particular attention to how disjunctive TVOR responses are channeled by these output neurons. In doing these studies, we will employ a new linear sled/rotator developed to our specifications by Accutronics, Inc. This new instrument will enable us to deliver precisely controlled linear (in the horizontal plane) or angular stimuli (about a yaw axis) in any combination to experimental subjects.