Eye Movement Maps in Mouse Superior Colliculus

项目概要/摘要 哺乳动物上级丘（SC）是整合视觉和其他功能的皮层下结构。 感官信息，以启动眼睛和头部的定向运动。SC的一个基本特征 组织是感觉输入和运动输出的表征是地形布置的， 对齐。虽然在理解视觉表征的发展方面取得了很大进展， 运动图如何形成并与视觉图对齐的SC仍然是未知的。为了采取 利用小鼠中可用的遗传工具，研究人员建议进行全面的 研究小鼠SC中运动地图的组织和发展。首先，电 微刺激将在SC的深层进行，以引起扫视样快速眼球运动， 小鼠眼动图的地形组织将通过系统地改变 在SC中的刺激部位，并确定诱发运动的幅度和方向。单机 还将在深层进行记录，以确定单个神经元如何编码眼球运动 方向和幅度，以及这些运动场如何在小鼠SC中映射。 实验将在从出生起就被剥夺视觉经验的小鼠和现有的转基因小鼠中进行。 这些实验将确定视觉输入是否改变了SC中的视觉地图。 为运动地图开发和视觉对齐提供指导性信号。在一起，拟议的 实验将提供第一个系统的映射的深层小鼠SC和启动研究 影响感觉运动发育的因素这些研究将有重要的影响， 对人类眼球运动障碍和其他疾病的理解和潜在治疗， 神经元连接的错误 6

Project Summary/Abstract The mammalian superior colliculus (SC) is a subcortical structure that integrates visual and other sensory information to initiate orienting movements of the eyes and head. A fundamental feature of SC organization is that the representations of sensory inputs and motor outputs are topographically arranged and aligned. While great progress has been made in understanding the development of the visual representation in the SC, how the motor maps are formed and aligned with the visual map remains unknown. In order to take advantage of the available genetic tools in mice, the investigators propose to perform a comprehensive investigation of the organization and development of motor maps in the mouse SC. First, electrical microstimulation will be conducted in the deep layers of the SC to evoke saccade-like rapid eye movements in mice. The topographic organization of the eye movement map will be revealed by systematically varying the stimulation sites in the SC and determining the amplitude and direction of the evoked movements. Single-unit recording will also be performed in the deep layers to determine how individual neurons encode eye movement direction and amplitude, and how such movement fields are mapped in the mouse SC. Second, the same experiments will be performed in mice deprived of visual experience from birth and in an existing transgenic mouse line that have altered visual maps in the SC. These experiments will determine whether visual inputs provide an instructive signal for motor map development and visuomotor alignment. Together, the proposed experiments will provide the first systematic mapping of the deep layers of the mouse SC and initiate studies on factors influencing sensorimotor development. These studies will have important implications for the understanding and potential treatment of human eye movement disorders and other diseases that result from miswiring of neuronal connections. 6