Vestibular Adaptation and Compensatory Mechanisms

描述（由申请人提供）：本研究的长期目标是了解前庭病变后凝视稳定系统的适应和代偿能力，并确定驱动前庭-眼反射适应的机制。对适应机制的理解将与运动学习相关，这是神经科学的一个基本问题，并将对我们理解人类如何适应前庭疾病具有实际意义。这项研究的一个功能性的、长期的结果将是为前庭疾病患者制定更合适的康复策略。这些康复策略可以作为其他神经肌肉运动障碍康复的模型。本研究的第一个目的是确定是否不规则释放的前庭传入事件负责产生非线性前庭-眼角反射（AVOR）。这将在松鼠猴的一系列行为和电生理实验中得到证实。猴子将经历景观诱导的AVOR适应；在适应性刺激过程中，在选定的时间点诱导不规则传入事件的可逆失活。将使用AVOR的前后适应措施来确定不规则传入信号在AVOR产生中的作用。在相同的动物中，使用相同的旋转和电刺激记录规则和不规则传入的放电特性。第二个目的是确定光诱导的AVOR适应是否会减少单侧前庭功能缺陷（UVD）后同侧和对侧旋转之间的缺陷和不对称性。在UVD恢复后，猴子将适应放大镜或CSA，使用旋转方向作为上下文线索，并从这种诱导的AVOR增益增加中恢复，以确定适应是否会导致功能缺陷减少。

DESCRIPTION (provided by applicant): The long-term goals of this research are to understand the adaptive and compensatory capabilities of the gaze stability systems following vestibular lesions and to identify the mechanisms that drive the adaptation of the vestibulo-ocular reflexes. An understanding of the adaptive mechanisms will be pertinent to motor learning, a fundamental question in neuroscience, and will have practical implications on our understanding of how humans adapt to vestibular disorders. A functional, long-term outcome of this research will be the development of more appropriate rehabilitation strategies for patients with vestibular disorders. These rehabilitation strategies may serve as models for the rehabilitation of other neuromuscular movement disorders. The first aim of the study is to determine if the irregularly discharging vestibular afferents are responsible for the generation of the nonlinear component of the angular vestibulo-ocular reflex (AVOR). This will be determined in a series of behavioral and electrophysiologic experiments in squirrel monkeys. Monkeys will undergo spectacle-induced adaptation of the AVOR; reversible inactivation of the irregular afferents will be induced at selected time epochs during the adaptation stimulus. Pre- and post-adaptation measures of the AVOR will be used to determine the role of the irregular afferent signal in the generation of the AVOR. In the same animals, the discharge properties of both regular and irregular afferents will be recorded using identical rotational and electrical stimuli. The second aim is to determine if optically induced adaptation of the AVOR will reduce the deficit and asymmetry between ipsilesional and contralesional rotations following a unilateral vestibular deficit (UVD). Following recovery from a UVD, monkeys will be adapted with either magnifying spectacles or with CSA using direction of rotation as the context cue, and the recovery from this induced increase in AVOR gain will be monitored to determine if adaptation will lead to reduced functional deficits.