Movement-related and preparatory activity in the reticulospinal system of the monkey
Movement-related and preparatory activity in the reticulospinal system of the monkey
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DOI：
10.1007/s00221-004-1956-4
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发表时间：
2004-12-01
影响因子：
2
通讯作者：
Davidson, AG
中科院分区：
文献类型：
--
作者：
Buford, JA;Davidson, AG
三只猴子（M. fascicularis）执行了一项从中心向外的二维到达任务，其中包括基于颜色编码的视觉空间提示的指示延迟间隔。记录内侧脑桥髓质网状结构（mPMRF）的神经活动以及手部运动。在 176 个具有运动相关活动的神经元中，109 个（62%）具有运动相关但没有准备活动（M 细胞），67 个（38%）同时具有运动相关和准备活动（MP 细胞）。眼电图分析表明，准备活动与眼球运动的控制不一致。在 Go 提示之前的指示延迟期间，肌电图 (EMG) 发生了轻微变化，但与运动相关的肌电图活动相比，这些变化很小。准备活动，如 EMG 活动，也仅限于 14 个 MP 细胞的指示延迟期结束时，但其余 53 个 MP 细胞 (30%) 的准备活动未反映在 EMG 中。 70% 的细胞的运动过程中的神经活动随着运动方向的变化而变化，但这种变化很少符合通常用于方向调节研究的循环统计；定向调整在准备活动中更不常见。这些数据表明，mPMRF 中的神经元在小的伸手动作期间受到强烈调节，但这种调节很少与手的轨迹相关。与中枢神经系统其他区域的文献研究结果一致，这些细胞中与运动准备相关的活动证据表明，这种功能分布在神经系统中，而不是仅限于大脑皮层的特征。
Three monkeys (M. fascicularis) performed a center-out, two-dimensional reaching task that included an instructed delay interval based on a color-coded visuospatial cue. Neural activity in the medial pontomedullary reticular formation (mPMRF) was recorded along with hand movement. Of 176 neurons with movement-related activity, 109 (62%) had movement-related but not preparatory activity (M cells), and 67 (38%) had both movement-related and preparatory activity (MP cells). EOG analyses indicated that the preparatory activity was not consistent with control of eye movements. There were slight changes in electromyograms (EMG) late in the instructed delay period before the Go cue, but these were small compared with the movement-related EMG activity. Preparatory activity, like the EMG activity, was also confined to the end of the instructed delay period for 14 MP cells, but the remaining 53 MP cells (30%) had preparatory activity that was not reflected in the EMG. Peri-movement neural activity varied with movement direction for 70% of the cells, but this variation rarely fit circular statistics commonly used for studies of directional tuning; directional tuning was even less common in the preparatory activity. These data show that neurons in the mPMRF are strongly modulated during small reaching movements, but this modulation was rarely correlated with the trajectory of the hand. In accord with findings in the literature from other regions of the CNS, evidence of activity related to motor preparation in these cells indicates that this function is distributed in the nervous system and is not a feature limited to the cerebral cortex.