Motor Learning & Neural Plasticity in Vestibular System

描述（由申请人提供）前庭眼反射（VOR）在头部运动期间稳定凝视并因此稳定中央凹图像。由疾病或发育变化引起的VOR缺陷会严重损害视力。VOR中的神经适应对于克服这些缺陷至关重要。在过去的几十年里，VOR及其适应性的研究一直集中在脑干和小脑通路的贡献。然而，大脑皮层在VOR中的作用在很大程度上仍未得到研究。最近的研究表明，额叶眼野（FEF）有直接的投射到脑干VOR通路和亚区的FEF链接到平稳眼动（FEFsem）的神经元表现出活动相关的眼球运动和头部运动，这表明在VOR的FEFsem的重要作用。该研究的目的是采用单单位记录和化学损伤的方法来研究FEFsem在VOR的产生和适应中的贡献。第一个目的是使用单单位记录技术来定量分析FEFsem神经元如何编码猴头部运动。最近，我们已经开发出一种范式，诱导强大的短期和长期的可塑性，在VOR，补偿平移头运动（TVOR）。该范式的一个新特征是，这些行为变化不是由视觉信息引导的，而是由任务的空间背景引导的，即目标是否在空间中静止或相对于头部固定。第二个目的是利用这种范式来研究FEFsem神经元在TVOR产生中的作用。本实验将提供更多的理解FEFsem在信息处理相关的任务背景和在自愿控制和适应的TVOR。第三个目的是通过可逆性失活FEFsem和研究其对TVOR产生和适应的影响来评估FEFsem的功能意义。这项研究将为了解基础前庭和动眼神经生理学以及改善人类前庭疾病的诊断和治疗提供重要知识。

DESCRIPTION (provided by applicant) The vestibulo-ocular reflex (VOR) stabilizes gaze and hence foveal images during head movements. Deficits in the VOR resulting from disease or changes in development can severely impair vision. Neural adaptation in the VOR is essential to overcome these deficits. Over the past several decades, the investigation of the VOR and its adaptation has been focused on the contributions of brainstem and cerebellar pathways. The contributions of cerebral cortex in the VOR, however, remain largely unexplored. Recent studies have demonstrated that the frontal eye field (FEF) has direct projections to brainstem VOR pathways and neurons in the subregion of the FEF linked to smooth eye movements (FEFsem) exhibit activity related to both eye movements and head movements, suggesting an important role for the FEFsem in the VOR. The objective of the proposed research is to employ single unit recording and chemical lesion approaches to study the contributions of the FEFsem in the generation and adaptation of the VOR. The first aim is to use single unit recording techniques to quantitatively analyze how the FEFsem neurons encode head motion in monkeys. Recently, we have developed a paradigm that induces robust short-term and long-term plasticity in the VOR that compensates for translational head movements (TVOR). A novel feature of the paradigm is that these behavioral changes are not guided by visual information but by the spatial context of the task, i.e. whether the target is stationary in space or fixed relative to the head. The second aim is to take advantage of this paradigm to study the role of the FEFsem neurons in the generation of the TVOR. This experiment will provide greater understanding of the FEFsem in the information processing related to the task context and in the voluntary control and adaptation of the TVOR. The third aim is to assess the functional significance of the FEFsem by reversibly inactivating the FEFsem and studying its effect on the generation and adaptation of the TVOR. This research will provide important knowledge for understanding the fundamental vestibular and oculomotor neurophysiology and improving the diagnosis and treatment of vestibular disorders in humans.