PREPARATION FOR MOVEMENT - NEURAL REPRESENTATIONS OF INTENDED DIRECTION IN 3 MOTOR AREAS OF THE MONKEY
PREPARATION FOR MOVEMENT - NEURAL REPRESENTATIONS OF INTENDED DIRECTION IN 3 MOTOR AREAS OF THE MONKEY
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DOI：
10.1152/jn.1990.64.1.133
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发表时间：
1990-07-01
影响因子：
2.5
通讯作者：
CRUTCHER, MD
中科院分区：
文献类型：
--
作者：
ALEXANDER, GE;CRUTCHER, MD
1.本研究的目的是比较三个相互关联的运动区域的神经元的功能特性，这些运动区域与视觉引导的肢体运动的规划和执行有关。所有这三个结构，辅助运动区（SMA），初级运动皮层（MC）和壳核，是基底节-丘脑皮质“运动回路”的组成部分。本报告的重点是与运动准备有关的神经元活动。2.五只恒河猴被训练来执行一项视觉跟踪任务，其中肘部运动是在有和没有事先指示的情况下进行的。为了将预备组（和肢体运动）的方向与紧张性（和阶段性）肌肉激活的任务相关模式分离，一些试验包括施加恒定扭矩负荷，该负荷反对或协助行为范式所需的运动。在工作臂对侧的SMA、MC和壳核的臂区记录单细胞活性。共研究了741个任务相关神经元，其中SMA内222个，MC内202个，壳核内317个。每个区域都包含相当大比例的表现出准备活动的神经元，即，细胞，显示任务相关的变化，放电率在postinstruction（准备）的时间间隔。SMA中含有较大比例的这种细胞（55%）比MC（37%）或壳核（33%）。SMA（32%）中仅显示预备活动的细胞比例是MC（11%）的三倍。在所有这三个领域，细胞，只显示准备活动往往位于更rostrally比细胞与运动相关的活动。在SMA的手臂区域内，微刺激诱发运动的部位的分布显示出相反的趋势：即，微兴奋位点主要局限于该区域的尾侧半。4.大多数与任务相关的准备活动的细胞表现出选择性激活的肘关节运动的预期在一个特定的方向（SMA，86%; MC，87%;壳核，78%），并在大多数情况下，准备活动被认为是独立的负载条件（SMA中80%，MC中83%，壳核中84%）。（400字处删节）
1. The purpose of this study was to compare the functional properties of neurons in three interrelated motor areas that have been implicated in the planning and execution of visually guided limb movements. All three structures, the supplementary motor area (SMA), primary motor cortex (MC), and the putamen, are components of the basal ganglia-thalamocortical “motor circuit.” The focus of this report is on neuronal activity related to the preparation for movement. 2. Five rhesus monkeys were trained to perform a visuomotor step-tracking task in which elbow movements were made both with and without prior instruction concerning the direction of the forthcoming movement. To dissociate the direction of preparatory set (and limb movement) from the task-related patterns of tonic (and phasic) muscular activation, some trials included the application of a constant torque load that either opposed or assisted the movements required by the behavioral paradigm. Single-cell activity was recorded from the arm regions of the SMA, MC, and putamen contralateral to the working arm. 3. A total of 741 task-related neurons were studied, including 222 within the SMA, 202 within MC, and 317 within the putamen. Each area contained substantial proportions of neurons that manifested preparatory activity, i.e., cells that showed task-related changes in discharge rate during the postinstruction (preparatory) interval. The SMA contained a larger proportion of such cells (55%) than did MC (37%) or the putamen (33%). The proportion of cells showing only preparatory activity was threefold greater in the SMA (32%) than in MC (11%). In all three areas, cells that showed only preparatory activity tended to be located more rostrally than cells with movement-related activity. Within the arm region of the SMA, the distribution of sites from which movements were evoked by microstimulation showed just the opposite tendency: i.e., microexcitable sites were largely confined to the caudal half of this region. 4. The majority of cells with task-related preparatory activity showed selective activation in anticipation of elbow movements in a particular direction (SMA, 86%; MC, 87%; putamen, 78%), and in most cases the preparatory activity was found to be independent of the loading conditions (80% in SMA, 83% in MC, and 84% in putamen).(ABSTRACT TRUNCATED AT 400 WORDS)