Neural Basis of Gaze Shifts

描述（由申请人提供）：人类和非人类都通过定位感兴趣的对象与环境相互作用。这样的反应通常是通过整合多个效应器的运动而产生的。该研究项目的长期目标是了解眼-头协调运动产生的视线（凝视）的变化。具体目标旨在描述前馈，反馈和互动机制，导致两组不同肌肉的协调控制。目光转移被认为是由一个编码期望的目光变化的命令触发的，脑干的结构决定了产生目光转移所需的眼睛和头部成分。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制定的。头部受限的跳眼运动是由一个保持其准确性的错误感知反馈回路控制的。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。它是保留了注视信号的准确性，还是只保留了跳眼成分？具体目标3将测试头部运动命令是否会影响注视转移的眼睛成分的动力学。特异性目标4将通过评估眼球运动神经元在眼球转移过程中的眼外跳输入，重新审视眼球转移过程中前庭眼反射的增益。总的来说，这些实验的结果将提供对注视转移的神经控制的见解，并为由动眼肌、前庭和颈椎疾病引起的缺陷提供诊断价值。我们通过定位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，但关于合作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).