Brainstem control of visual orienting

描述（由申请人提供）：在复杂行为的表现中产生平稳协调的动作是神经系统的基本目标。要做到这一点，感官信息必须持续整合，以构建世界上物体的表征。这一关键功能需要能够区分自我产生的运动和物体运动，整合不同的感觉信息，并计划和执行同步运动行为。协调运动选择和执行的神经结构之间的相互作用，以及解决稳定反射和运动命令之间固有冲突的机制，是理解协调动作的神经控制的关键问题。眼-头协调运动的神经控制是一个实验系统，为研究视觉定向行为的神经机制提供了重要的见解。将视线（凝视）指向有趣的物体，增强了我们对物体的感知，并提供了一种构建和维护世界内部模型的方法。这些注视方向的变化通常是通过眼睛和头部的协调来完成的，为研究定向行为的神经控制、多身体部分的协调、空间定向和感觉信息转化为运动命令提供了一个很好的模型系统。本研究的目的是阐明在视觉定向运动的背景下协调所需的神经计算和机制。我们将记录脑干中神经元的活动，当他们的头部可以自由移动时，他们的目光会发生变化。我们将确定这些细胞的活动与凝视、眼睛和/或头部运动的度量和/或运动学之间的关系，我们将描述巨细胞网状核细胞的活动特征，并确定它们在产生头部运动中的作用。我们将同时记录上丘（SC）细胞和SC下游细胞的活动，以揭示将SC信号转化为移动眼睛和头部所需的命令的潜在机制。这些实验将为神经系统将感觉输入转化为协调行动的方式提供令人兴奋和新颖的见解。

DESCRIPTION (provided by applicant): Producing smoothly coordinated movements during performance of complex behaviors is an essential goal of the nervous system. To accomplish this, sensory information must be integrated continuously in order to construct a representation of objects in the world. This critical function requires the ability to distinguish between self-generated and object motion, to integrate diverse sensory information, and to plan and execute simultaneous motor behaviors. The interactions among neural structures that mediate selection and execution of coordinated movements, and the mechanisms that resolve the inherent conflict between stabilizing reflexes and motor commands are critical issues in understanding the neural control of coordinated action. The neural control of coordinated eye-head movements is an experimental system that has provided significant insights into the neural mechanisms mediating visual orienting behaviors. Directing the line of sight (gaze) towards interesting objects enhances our perception of the object and provides a way to construct and maintain an internal model of the world. These changes in gaze direction are generally accomplished by coordinating the eyes and head, and provide an excellent model system for studying the neural control of orienting behaviors, the coordination of multiple body segments, spatial orientation and transformation of sensory information into motor commands. The goals of the proposed research are to elucidate the neural computations and mechanisms required for coordination within the context of visual orienting movements. We will record the activity of neurons in the brainstem during gaze shifts made when the head is free to move. We will determine the relationship between the activity of these cells and the metrics and/or kinematics of the gaze, eye and/or head movements, we will characterize the activity of cells in the nucleus reticularis gigantocellularis and identify their role in generation of head movements, and we will record activity simultaneously from cells in the superior colliculus (SC) and cells downstream from the SC in an effort to reveal the underlying mechanisms that transform SC signals into the commands needed to move the eyes and head. These experiments will provide exciting and novel insight into the ways in which the nervous system converts sensory inputs into coordinated actions.