Jackson Andrew, Mavoori Jaideep, Fetz Eberhard E
Department of Physiology and Biophysics, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-7290, USA.
J Neurophysiol. 2007 Jan;97(1):360-74. doi: 10.1152/jn.00710.2006. Epub 2006 Oct 4.
Traditionally, the neural control of movement has been studied by recording cell activity in restrained animals performing repetitive, highly trained tasks within a restricted workspace. However, the degree to which results obtained under these conditions are valid during natural, unconstrained behavior remains unknown. Using an autonomous, implantable recording system, we examined the relationships between the firing of motor cortex cells and forearm muscle activity in primates under three behavioral conditions: performance of a conventional torque-tracking task, unrestrained behavior, and natural sleep. We found strong correlations over long periods of daytime activity, suggesting a consistent relationship between cortex and muscles across the repertoire of awake behavior. The range of correlation values was comparable during task performance, but many individual cells exhibited significant differences across conditions. During the night, phases of sleep were associated with a cyclical pattern of cell and muscle activity. Across the population, the strength of cell-muscle correlations was related to preferred direction for daytime but not nighttime activity. The relationship of cells to behavior remained consistent over periods of several weeks. These findings extend the interpretation of results obtained under constrained conditions and are relevant to the development of neural prostheses for restoring natural movements to patients with motor deficits.
传统上，运动的神经控制研究是通过记录在受限工作空间内执行重复性、高度训练任务的受限动物的细胞活动来进行的。然而，在这些条件下获得的结果在自然、不受约束的行为中有效的程度仍然未知。我们使用一个自主的、可植入的记录系统，在三种行为条件下研究了灵长类动物运动皮层细胞的放电与前臂肌肉活动之间的关系：执行传统的扭矩跟踪任务、不受约束的行为和自然睡眠。我们发现在白天长时间活动期间存在很强的相关性，这表明在清醒行为的全部范围内，皮层和肌肉之间存在一致的关系。在任务执行期间，相关值的范围是可比的，但许多单个细胞在不同条件下表现出显著差异。在夜间，睡眠阶段与细胞和肌肉活动的周期性模式相关。在整个群体中，细胞 - 肌肉相关性的强度与白天活动的偏好方向有关，但与夜间活动无关。细胞与行为的关系在数周时间内保持一致。这些发现扩展了对在受限条件下获得的结果的解释，并且与开发用于恢复运动功能障碍患者自然运动的神经假体相关。
