Neural Basis of Gaze Shifts

描述（由申请人提供）：人类和非人类一样，通过定向到感兴趣的对象与环境互动。这样的响应通常通过整合跨多个效应器的运动来生成。研究计划的长期目标是了解协调的眼-头运动，从而产生视线（凝视）的变化。具体的目标是描绘前馈，反馈和互动机制，导致两个不同的肌肉群的协调控制。视线转移被认为是由编码所需视线变化的命令触发的，脑干中的结构决定了产生视线转移所需的眼睛和头部组件。具体目标1旨在确定在脑桥网状结构中，眼睛和头部运动控制的单独命令是如何制定的。头部限制扫视眼球运动控制的误差传感反馈电路，保持其准确性。具体目标2将研究反馈原理如何外推到头部不受限制的凝视转移。它是保持凝视信号的准确性还是仅仅保持其扫视眼睛分量？特定目标3将测试头部移动命令是否会影响视线转移的眼睛组件的动态。特定目标4将通过评估凝视转移期间眼外运动神经元的扫视输入，重新审视凝视转移期间前庭眼反射的增益。总的来说，这些实验的结果将提供洞察力的注视转移的神经控制，并提供诊断价值的赤字所造成的眼病，前庭和颈椎疾病。公共卫生相关性我们通过定向感兴趣的对象与环境互动。协调的眼-头运动是一种基本的定向反应，可以改变视线，但关于协调控制这两组肌肉的机制仍然存在许多问题。描绘产生这种整合运动的神经回路将为理解空间定向缺陷（眩晕）和运动控制障碍（斜颈，帕金森症，斜视）提供诊断价值。

DESCRIPTION (provided by applicant): Humans and nonhumans alike interact with the environment by orienting to objects of interest. Such responses are typically generated by integrating movements across multiple effectors. The long- term objective of the research program is to understand the coordinated eye-head movements that produce a change in the line of sight (gaze). The specific aims are designed to delineate feedforward, feedback and interactive mechanisms that result in the coordinated control of two different groups of muscles. A gaze shift is thought to be triggered by a command encoding the desired change in gaze, and structures in the brain stem determine the eye and head components required to generate the gaze shift. Specific Aim 1 seeks to identify where in the pontine reticular formation are the separate commands of eye and head movement control formulated. Head-restrained saccadic eye movements are controlled by an error-sensing feedback circuit that preserves its accuracy. Specific Aim 2 will investigate how the feedback principle extrapolates to head-unrestrained gaze shifts. Does it preserve accuracy of the gaze signal or just its saccadic eye component? Specific Aim 3 will test whether head movement commands can influence the dynamics of the eye component of gaze shift. Specific Aim 4 will revisit the gain of the vestibulo-ocular reflex during gaze shifts by evaluating the saccadic input into the extraocular motoneurons during gaze shifts. Overall, the results of these experiments will provide insights into the neural control of gaze shifts and offer diagnostic value for deficits resulting from oculomotor, vestibular and cervical disorders. PUBLIC HEALTH RELEVANCE We interact with our environment by orienting to objects of interest. A coordinated eye-head movement is a basic orienting response that shifts the line of sight, but many questions remain about the mechanisms that cooperatively control the two groups of muscles. Delineating the neural circuits that produce such integrated movements will provide diagnostic value for understanding spatial orientation deficits (vertigo) and motor control disorders (torticollis, Parkinsonism, strabismus).