Neural Basis of Gaze Shifts

描述(申请人提供)：人类和非人类一样，通过指向感兴趣的对象与环境互动。这样的响应通常通过对多个效应器上的运动进行积分来生成。该研究计划的长期目标是了解导致视线(凝视)变化的眼头协调运动。具体目标旨在勾勒出前馈、反馈和互动机制，从而实现两组不同肌肉的协调控制。凝视转移被认为是由编码所需凝视变化的指令触发的，脑干的结构决定了产生凝视转移所需的眼睛和头部成分。具体目标1试图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形成的。头约束的眼球跳动由误差感应反馈电路控制，以保持其准确性。具体目标2将研究反馈原理如何外推到不受限制的头部凝视转移。它是保持凝视信号的准确性，还是只保留其跳动的眼睛成分？《特定目标3》将测试头部运动指令是否会影响凝视转移眼部成分的动态变化。具体目标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-眼睛反射的获得。总体而言，这些实验的结果将为凝视转移的神经控制提供洞察力，并为眼球运动、前庭和颈椎疾病造成的缺陷提供诊断价值。公共卫生相关性我们通过定位感兴趣的对象来与环境互动。协调的眼头运动是改变视线的基本定向反应，但关于协同控制这两组肌肉的机制仍然存在许多问题。描绘产生这种综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、帕金森病、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).