Selective neuronal discharge in monkey putamen reflects intended direction of planned limb movements.
Selective neuronal discharge in monkey putamen reflects intended direction of planned limb movements.
复制标题
猴壳核中的选择性神经元放电反映了计划的肢体运动的预期方向。
DOI：
10.1007/bf00247293
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发表时间：
1987
影响因子：
2
通讯作者：
Alexander,GE
中科院分区：
文献类型：
--
作者：
Alexander,GE
记录了恒河猴（Macaca mulatta）的壳核的单细胞活动，这些活动在有或没有关于即将发生的运动方向的预先准备“设置”的情况下进行肢体运动。这些猴子被训练执行肘部步进跟踪任务，每次试验都要求受试者做出两个连续的动作，这些动作在方向、幅度、速度和肌肉模式方面几乎相同。第一个运动之前有一个前段，即“指令前”阶段，在此期间，猴子无法预测即将到来的运动的方向（弯曲/伸展）。第二个运动之前也有一个可变的前段，即“指令后”时期，但在此间隔期间，猴子意识到即将发生的运动方向，因为它总是需要与第一个运动的方向相匹配。为了将运动组（和肢体运动）的方向与与任务表现相关的强直（和阶段性）肌肉激活模式分开，一些试验包括应用扭矩负载，以对抗或辅助行为范式所需的运动。在 232 个壳核神经元（全部位于手臂代表区域内）中观察到两种主要形式的任务相关活动，其放电模式显示出与行为范式的一个或多个特征显着相关。 “运动相关”神经元（178/232，76.7%）选择性地与肘部的屈曲或伸展运动相关放电。 “设定相关”神经元（47/232，20.3%）在整个指令后期间表现出持续的、选择性的放电变化，而猴子需要保持关于即将发生的运动方向的准备设定。广泛的肢体和轴向肌电图记录显示，没有证据表明任务相关的活动模式与那些表征设定相关神经元的活动模式相当，巩膜搜索线圈记录显示，任务执行过程中，设定相关的神经元活动与凝视方向或眼球运动的方向和时间之间没有关系。只有一小部分（7/232，3.0%）的任务相关神经元同时表现出运动和设定相关的活动。在大多数情况下（37/47，79%），与设定相关的活动是有方向选择性的，放电的幅度反映了即将发生的运动方向。方向选择性的、与设定相关的活动不表现出对负载条件的依赖性，似乎仅反映即将到来的计划运动的预期方向，而不反映此类运动所需的预期肌肉激活力或模式。
Single cell activity was recorded from the putamen in rhesus monkeys (Macaca mulatta) performing limb movements made both with and without a preceding preparatory “set” concerning the impending direction of movement. The monkeys were trained to perform an elbow step-tracking task, each trial of which required the subject to make two sequential movements that were virtually identical in terms of their direction, amplitude, velocity and muscle pattern. The first movement was preceded by a foreperiod, the “pre-instruction” period, during which the monkey could not predict the direction (flexion/extension) of the forthcoming movement. The second movement was also preceded by a variable foreperiod, the “post-instruction” period, but during this interval the monkey was aware of the impending direction of movement because it was always required to match that of the first movement. To dissociate the directions of motor set (and limb movement) from the patterns of tonic (and phasic) muscular activation associated with task performance, some trials included the application of torque loads that either opposed or assisted the movements required by the behavioral paradigm. Two principal forms of task-related activity were observed among the 232 putamen neurons (all located within the region of arm representation) whose discharge patterns showed significant relations to one or more features of the behavioral paradigm. “Movement-related” neurons (178/232, 76.7%) discharged selectively in association with either flexion or extension movements of the elbow. “Set-related” neurons (47/232, 20.3%) manifested sustained, selective changes in discharge throughout the post-instruction period, while the monkey was required to maintain a preparatory set concerning the impending direction of movement. Extensive limb and axial EMG recordings showed no evidence of task-related activity patterns comparable to those that characterized the set-related neurons, and scleral search coil recordings showed no relationship between set-related neuronal activity and either the direction of gaze or the direction and timing of eye movements during task performance. Only a small percentage (7/232, 3.0%) of the task-related neurons showed both movement-and set-related activity. In most cases (37/47, 79%), set-related activity was directionally selective, with the magnitude of discharge reflecting the impending direction of movement. Exhibiting no dependence upon the loading conditions, the directionally selective, set-related activity appeared to reflect only the intended direction of forthcoming, planned movements, and not the anticipated force or pattern of muscular activation that such movements would require.