A Neurophysiological Study of Roles of Motor Areas in Primate Cortex for Mastication

在视觉引导的下颌运动任务中，分析了运动前区皮层（PMv）和初级运动皮层（MI）腹侧部分的神经元活动。根据观察到的神经元活动类型，当猴子闭上或张开嘴以响应视觉刺激时，PMv神经元可以分为三类：1）信号相关神经元，其对视觉刺激作出短暂反应，2）运动相关神经元，其对下颌张开和/或下颌闭合运动进行时间锁定，（3）在保持颌位的同时，集合相关神经元的活动逐渐增强。然而，所有MI神经元表现出运动相关的活动，并作出不同的反应之间的关闭和开放的动态阶段。这些结果表明，PMv神经元可能参与运动准备，启动和控制下颌运动和任务行为的基础上的视觉信息，和MI神经元可能参与控制下颌运动，特别是咀嚼肌的收缩。

Neuronal activities in the ventral part of the premotor cortex (PMv) and the primary motor cortex (MI) were analyzed during a visually guided jaw movement task. Based on the type of neuronal activity observed, when monkeys closed or opened their mouths in response to a visual stimulus, PMv neurons could be classified into three categories : 1)signal-related neurons, which transiently responded to visual stimuli, 2)movement-related neurons, which were time-locked to Jaw opening and/or jaw closing movements, and 3)set-related neurons which exhibited gradually increasing activities while jaw position was maintained. However, all MI neurons exhibited movement-related activities and responded differently between the closing and opening dynamic phases. These results suggest that PMv neurons may be involved in motor preparation, initiation and control of jaw movements and task behavior based on visual information, and that MI neurons may be involved in controlling jaw movements, especially contraction of the masticatory muscles.