Vestibular and Visual Control of Eye Movement

描述（由申请人提供）：动作学习是通过练习使动作变得流畅和准确的过程。运动学习依赖于大脑中一个叫做小脑的区域，小脑功能障碍的患者动作笨拙，不协调。这个项目研究了指导运动学习的错误信号。小脑或相关神经回路中的哪些神经元监控运动的准确性，并确定何时需要更新控制该运动的运动程序？几十年来，人们一直认为，从下橄榄体到小脑的“攀爬纤维”输入提供了指导运动学习的唯一指导性信号。然而，我们最近发现，运动学习可以在不引起攀爬纤维反应的训练条件下诱导。拟议的实验分析这种攀爬纤维独立的运动学习的组成部分。特别是，我们将研究控制这一学习成分的指导信号的起源，我们将确定哪些方面的运动可以和不能调节。 本计画利用眼球运动的实验易处理性，特别是前庭眼反射（vestibulo-ocular reflex，VOR）来分析运动学习的神经机制。VOR是一种反射性的眼球运动，它通过在与头部运动相反的方向上唤起眼球运动来减少视网膜上视觉图像的运动。运动学习的一种形式，称为VOR适应，当图像运动持续与头部转动相关联时，通过逐渐校正反射来校准VOR。VOR适应对于确保头部转动期间的足够视敏度以及对于响应于生物体或其环境中的变化（诸如随着生长和发育、衰老、外周或中枢神经系统损伤或戴上一副新眼镜而发生的变化）恢复空间中的适当运动和感知定向是必不可少的。 公共卫生相关性：该项目将提高我们对控制学习诱导的神经机制的理解。这一认识的提高应有助于设计有效的补救策略的学习和记忆障碍和康复策略的中枢神经系统或外周损伤。

DESCRIPTION (provided by applicant): Motor learning is the process by which movements become smooth and accurate through practice. Motor learning depends on a brain region called the cerebellum, and patients with cerebellar dysfunction have clumsy, uncoordinated movements. This project examines the error signals that guide motor learning. Which neurons in the cerebellum or related neural circuitry monitor the accuracy of a movement, and determine when the motor program controlling that movement needs to be updated? For decades it was thought that the "climbing fiber" input to the cerebellum from the inferior olive provided the sole instructive signal guiding motor learning. However, we recently showed that motor learning could be induced under training conditions that elicit no response in the climbing fibers. The proposed experiments analyze this climbing fiber-independent component of motor learning. In particular, we will examine the origin of the instructive signals controlling this component of learning, and we will determine which aspects of movement it can and cannot regulate. This project capitalizes on the experimental tractability of eye movements, in particular the vestibulo-ocular reflex (VOR), to analyze the neural mechanisms of motor learning. The VOR is a reflexive eye movement that reduces motion of visual images on the retina by evoking eye movements in the opposite direction to head movements. A form of motor learning, known as VOR adaptation, calibrates the VOR by gradually correcting the reflex when image motion is persistently associated with head turns. VOR adaptation is essential for ensuring adequate visual acuity during head turns and for restoring proper motor and perceptual orientation in space in response to changes in the organism or its environment, such as occur with growth and development, aging, injury to the peripheral or central nervous system or the donning of a new pair of spectacles. PUBLIC HEALTH RELEVANCE: This project will improve our understanding of the neural mechanisms controlling the induction of learning. This improved understanding should facilitate the design of effective remediation strategies for disorders of learning and memory and rehabilitation strategies for CNS or peripheral injury.