PHYSIOLOGY OF OCULOMOTOR PREMOTOR PATHWAYS

动眼运动前通路的生理学

• 批准号: 2161825
• 负责人: Robert A. McCrea
• 金额: $ 15.71万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-04-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2161825
• 关键词: Saimiri; antidromic impulse; behavior test; brain electrical activity; cerebellum; head movements; neural information processing; neuroanatomy; neurons; neurophysiology; oculomotor nuclei; reticular formation; smooth pursuit eye movement; vestibular pathway; vestibuloocular reflex; visual pathways

The goal of the proposed studies is to elucidate the physiological characteristics of the pathways in the brain that are involved in the generation and voluntary control of the vestibulo-ocular reflex (VOR). Previous studies showed that monkeys utilize two mechanisms to voluntarily cancel their VOR (VORC). One mechanism involves a reduction in the head movement sensitivity of the secondary vestibular neurons that project to the abducens nucleus, the position-vestibular-pause (PVP) neurons. A second mechanism involves the generation of a smooth pursuit eye movement in the opposite direction to the VOR. The specific aims of the present proposal are to study the behavioral circumstances and neural mechanisms that are involved in the use of each of the mechanisms for voluntarily controlling the VOR. There are four specific aims. 1) In order to more precisely determine the behavioral circumstances in which the non-pursuit mechanism is recruited, behavioral experiments will be carried out in which the head will be passively perturbed during head free gaze pursuit of a visual target that is moving predictably and unpredictably. The gain of the VOR evoked by passive head perturbations will be studied as a function of head, gaze and target movement parameters. 2) The firing behavior of PVP neurons will be recorded in head free monkeys during gaze pursuit using the chronically implanted microwire in order to determine what signals are generated in secondary VOR pathways during head free gaze pursuit. 3) The possibility that inputs from the cerebellum or the reticular formation cause the head velocity sensitivity of secondary PVP neurons to decrease during VORC will be tested by recording from Purkinje cells in the flocculus and nodulus and neurons in the reticular formation near the abducens nucleus during unpredictable steps in head acceleration that are generated during VORC and during the VOR. 4) Several observations suggest that the abducens nucleus must receive inputs from cells whose activity is specifically related to smooth pursuit eye movements in order for the effects of residular head movement signals in VOR pathways to be canceled. An attempt will be made to determine whether the smooth pursuit neurons in the propositus nucleus and the adjacent medial vestibular nucleus whose activity is closely related to smooth pursuit eye movements project to the abducens nucleus by using the technique of spike triggered averaging of lateral rectus or abducens potentials combined with antidromic stimulation of the abducens nucleus.

拟议研究的目的是阐明生理 大脑中涉及的途径的特征 前庭形式反射（VOR）的产生和自愿控制。 先前的研究表明，猴子利用两种机制自愿 取消他们的VOR（VORC）。 一种机制涉及减小头部 次生前庭神经元的运动灵敏度，该神经元投射到 拟核，位置 - 诊断（PVP）神经元的核。 一个 第二种机制涉及产生平稳的追击眼运动 在与VOR相反的方向上。 当前的具体目的 建议是研究行为环境和神经机制 使用的每种机制自愿使用 控制VOR。 有四个具体目标。 1）为了更多 精确地确定非伪装的行为环境 招募机制，将进行行为实验，其中 在自由凝视追捕时，头部将被动地干扰 视觉目标可以预见，无法预测。 收益 被动头部扰动引起的VOR将作为功能研究 头部，凝视和目标运动参数。 2）发射行为 PVP神经元将在凝视追捕过程中记录在无头猴子中 慢性植入的微孔以确定哪些信号是 在自由凝视追捕过程中以次级VOR途径产生。 3） 小脑或网状形成的输入的可能性 导致次级PVP神经元的头部速度敏感性降低 在VORC期间，将通过记录来自Purkinje细胞中的Purkinje细胞的测试 在网状地面形成中的絮状和nodulus和nodulus和神经元 在不可预测的头部加速步骤中，核的核心是 在VORC和VOR期间生成。 4）一些观察表明 外套的核必须从活性是的细胞中接收输入 特别与平稳的追捕眼动作有关 在VOR途径中驻留的驻扎头部移动信号的影响要取消。 将尝试确定是否在 螺旋核核和相邻的内侧前庭核的核 活动与平稳的追捕眼动计划密切相关 使用尖峰技术触发平均 外侧直肠或外侧势与抗刺激结合的电位 外套核的核心。