Does cerebellar cortex function as a forward internal model for motor control?

描述（由申请人提供）： 运动控制理论家假设，快速协调运动的产生需要控制电路，该控制电路可以通过提供对运动命令导致的后果的估计来绕过感觉反馈延迟。该控制元件被称为前向内部模型，其接收运动命令的传出副本和关于当前状态的信息，以便预测肢体的未来状态（即，运动学变量，如位置和速度）。先前的心理物理学、成像和患者案例研究表明，小脑是实现内部模型的可能位置。然而，很少有电生理学的研究，调查是否从小脑神经元的放电是一致的前向内部模型的属性。本项目的最终目标是评估是否简单的尖峰发射浦肯野细胞（PC）在小叶IV-VI的中间/外侧小脑区是一致的输出从一个向前的内部模型。虽然没有一个单一的结果将最终证明这一假设，两个电生理学实验研究猕猴的手部运动，提出了测试的几个方面的内部模型。目标1将研究PC射击是否以任务无关的方式预测未来的手部运动学。目标2将进一步评估模型的适应性，以及改变模型输入是否会改变预测的运动学。结果将表明，PC射击是不兼容的输出预期从一个向前的模型或提供坚实的支持，为未来的实验。 公共卫生相关性： 增加健康小脑功能的知识对于理解小脑脑损伤或疾病如何在临床上表现并导致运动协调，学习和运动时机的缺陷至关重要。在运动学习任务期间记录浦肯野细胞（小脑皮层中的一种特定类型的神经元）的活动可能会增加对这些细胞如何作为网络编码运动变量和学习新运动任务的理解。也许最重要的是，关于协调运动所需的控制参数的见解可能会为运动障碍患者带来更具体的康复治疗，并改进控制智能假肢的算法。

DESCRIPTION (provided by applicant): Motor control theorists have postulated that production of rapid, coordinated movements requires control circuitry that can bypass sensory feedback delays by providing an estimate of the consequences resulting from a motor command. This control element, termed a forward internal model, receives an efferent copy of the motor command and information about the current state in order to predict the future state of the limb (i.e., kinematic variables like position and velocity). Previous psychophysical, imaging, and patient case studies suggest that the cerebellum is a possible location for implementation of an internal model. However, few electrophysiological studies have investigated whether the firing discharge from cerebellar neurons is consistent with the properties of a forward internal model. The ultimate goal of this project is to evaluate whether the simple spike firing from Purkinje cells (PCs) in lobules IV-VI of the intermediate/lateral cerebellar zones is consistent with output from a forward internal model. Although no single result will conclusively prove this hypothesis, two electrophysiology experiments examining hand movements in rhesus macaques are proposed to test several aspects of a forward internal model. Aim 1 will examine whether PC firing predicts future hand kinematics in a task-independent manner. Aim 2 will further evaluate model adaptability and whether changing model inputs alters predicted kinematics. The results will either show that PC firing is incompatible with the output expected from a forward model or provide solid support for future experiments. PUBLIC HEALTH RELEVANCE: An increased knowledge of healthy cerebellar function is essential for understanding how cerebellar brain injury or disease might manifest clinically and lead to deficits in motor coordination, learning, and movement timing. Recording activity from Purkinje cells, a specific type of neuron in the cerebellar cortex, during movement learning tasks may lead to increased understanding of how these cells act as a network to encode movement variables and learn new motor tasks. Perhaps most importantly, insights regarding the control parameters required for coordinated movements may lead to more specific rehabilitation therapies for patients with movement disorders and improved algorithms for controlling smart prosthetics.