Ghosh Soumya, Putrino David, Burro Bianca, Ring Alexander
Centre for Neuromuscular & Neurological Disorders, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia.
Somatosens Mot Res. 2009 Jun;26(2):31-49. doi: 10.1080/08990220903098308.
In order to study how neurons in the primary motor cortex (MI) are dynamically linked together during skilled movement, we recorded simultaneously from many cortical neurons in cats trained to perform a reaching and retrieval task using their forelimbs. Analysis of task-related spike activity in the MI of the hemisphere contralateral to the reaching forelimb (in identified forelimb or hindlimb representations) recorded through chronically implanted microwires, was followed by pairwise evaluation of temporally correlated activity in these neurons during task performance using shuffle corrected cross-correlograms. Over many months of recording, a variety of task-related modulations of neural activities were observed in individual efferent zones. Positively correlated activity (mainly narrow peaks at zero or short latencies) was seen during task performance frequently between neurons recorded within the forelimb representation of MI, rarely within the hindlimb area of MI, and never between forelimb and hindlimb areas. Correlated activity was frequently observed between neurons with different patterns of task-related activity or preferential activity during different task elements (reaching, feeding, etc.), and located in efferent zones with dissimilar representation as defined by intracortical microstimulation. The observed synchronization of action potentials among selected but functionally varied groups of MI neurons possibly reflects dynamic recruitment of network connections between efferent zones during skilled movement.
为了研究初级运动皮层（MI）中的神经元在熟练运动过程中是如何动态连接在一起的，我们在经过训练使用前肢执行够取和取回任务的猫身上，同时记录了许多皮层神经元的活动。通过长期植入的微丝记录与够取前肢对侧半球的MI（在已确定的前肢或后肢代表区域）中与任务相关的锋电位活动，随后使用重排校正互相关图对这些神经元在任务执行期间的时间相关活动进行成对评估。在数月的记录过程中，在各个传出区域观察到了多种与任务相关的神经活动调制。在任务执行期间，MI前肢代表区域内记录的神经元之间经常出现正相关活动（主要是在零或短潜伏期处的窄峰），在MI后肢区域内很少出现，在前肢和后肢区域之间从未出现。在具有不同任务相关活动模式或在不同任务元素（够取、进食等）期间具有优先活动的神经元之间，以及位于通过皮层内微刺激定义的具有不同代表区域的传出区域中的神经元之间，经常观察到相关活动。在选定但功能不同的MI神经元组中观察到的动作电位同步，可能反映了熟练运动期间传出区域之间网络连接的动态募集。
