OTOLITH OCULAR REFLEXES--PHYSIOLOGY AND ADAPTIVE CONTROL

前庭眼反射（VORs）负责维持稳定性 头部运动时视网膜上的图像。许多行为 角运动控制的特点和神经生理机制 VOR已被阐明。相对而言， 耳石眼反射的组织。 这些反射可以分为 根据代偿性眼球运动的类型分为三类 由其激活而产生。眼反滚动是耳石眼 眼球扭转反射：引起眼睛围绕视线转动的反射 以响应动态和静态横向头部倾斜。平移线性 VOR是眼动响应于动态线性运动而发生的运动 头部的等速旋转诱发的眼球震颤 偏离垂直轴是由角速度信号产生的， 耳石活动的中央处理。前庭神经传入 神经支配耳石不能区分运动导致 这三个答案中的每一个。该项目中描述的研究将 定义涉及规范和自适应控制的机制， 耳石眼反射 三维和聚散眼球运动以及单单位 前庭神经核的活动将被记录在警觉的松鼠中 双侧半规管失活前后的猴 进行封堵。与下列过程有关的假设 将测试区分倾斜和平移反应。的作用 角速度信号，相位紧张性反应的不规则 耳石传入神经的放电和耳石的频率特异性过滤 将确定这些过程中的信号。生理 前庭核神经元参与耳石-眼神经系统的特性 控制将被定义。耳石和半规管的轮廓 这些神经元的传入输入将被识别为与 平移和倾斜刺激。适应研究介绍 视动刺激与产生特定 耳石和半规管激活的轮廓将提供进一步的 用于区分这些反应的信号信息。转让 调整VOR增益以适应不同组合的 半规管和耳石活动将确定点 在这些途径的融合，并确定机制参与生成 耳石活动的角速度信号。 本研究将增进我们对耳石-眼反应的了解 以及VOR短期适应过程。这些研究 与人类功能障碍的诊断和治疗直接相关 耳石眼反射

Vestibulo-ocular reflexes (VORs) are responsible for maintaining stability of images on the retina during head movements. Many of the behavioral features and neurophysiological mechanisms underlying control of angular VORs have been elucidated. Comparatively little is known about the organization of otolith-ocular reflexes. These reflexes can be divided into three categories according to the type of compensatory eye movements arising from their activation. Ocular counterrolling is the otolith-ocular reflex that causes torsional movement of the eyes around a line of sight in response to dynamic and static lateral head tilt. Translational linear VORs are eye movements that occur in response to dynamic linear movements of the head. The nystagmus induced by constant velocity rotation about an off-vertical axis results from an angular velocity signal generated by central processing of otolith activity. Vestibular-nerve afferents innervating the otoliths cannot distinguish between movements leading to each of these three responses. Research described in this project will define mechanisms involved in specification and adaptive control of otolith-ocular reflexes. Three dimensional and vergence eye movements as well as single-unit activity in the vestibular nuclei will be recorded in alert squirrel monkeys before and after bilateral inactivation of all semicircular canals with a plugging procedure. Hypotheses related to processes that distinguish tilt from translational responses will be tested. The role of angular velocity signals, phasic-tonic responses of irregularly discharging otolith afferents, and frequency-specific filtering of otolith signals in these processes will be determined. The physiological properties of neurons in the vestibular nuclei involved in otolith-ocular control will be defined. Profiles of otolith and semicircular canal afferent inputs to these neurons will be identified in relation to translational and tilt stimuli. Studies of adaptation introduced by optokinetic stimuli in association with motions producing specific profiles of otolith and semicircular canal activation will provide further information about signals used to distinguish these responses. Transfer of adapted VOR gain to reflexes induced by differing combinations of semicircular canal and otolith activity will identify points of convergence in these pathways and define mechanisms involved in generation of angular velocity signals from otolith activity. This research will enhance our understanding of otolith-ocular responses and the processes involved in short-term VOR adaptation. The studies are directly relevant to the diagnosis and treatment of dysfunction in human otolith-ocular reflexes.