Overlap of internal models in motor cortex for mechanical loads during reaching
Overlap of internal models in motor cortex for mechanical loads during reaching
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DOI：
10.1038/nature00834
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发表时间：
2002-06-27
期刊：
影响因子：
64.8
通讯作者：
Scott, SH
中科院分区：
文献类型：
--
作者：
Gribble, PL;Scott, SH
人类运动系统的一个特点是它能够根据不同的环境条件调整运动模式，比如当一名熟练的冰球运动员在有或没有防护装备的情况下准确地射出冰球时。每个物体(棍子、肩垫、肘垫)对肢体施加不同的负荷，运动神经科学中的一个关键问题是了解大脑如何在不同的机械环境下控制运动(1，2)。我们通过训练非人类灵长类动物在施加和不施加粘性负荷的情况下进行伸展运动来解决这个问题，然后检查了每种负荷条件下初级运动皮质(MI)的神经表示。尽管肩部和肘部的负荷是机械独立的，我们发现一些神经元对这两个单关节负荷都有反应。此外，单个神经元在多关节负荷期间的活动变化可以从它们对从属的单关节负荷的反应中预测出来。这些发现表明，MI中不同机械环境的神经表征是以高度结构化的方式组织起来的，这可能为如何从更简单的运动任务中学习复杂的运动行为提供神经基础。
A hallmark of the human motor system is its ability to adapt motor patterns for different environmental conditions, such as when a skilled ice-hockey player accurately shoots a puck with or without protective equipment. Each object (stick, shoulder pad, elbow pad) imparts a distinct load upon the limb, and a key problem in motor neuroscience is to understand how the brain controls movement for different mechanical contexts(1,2). We addressed this issue by training non-human primates to make reaching movements with and without viscous loads applied to the shoulder and/or elbow joints, and then examined neural representations in primary motor cortex (MI) for each load condition. Even though the shoulder and elbow loads are mechanically independent, we found that some neurons responded to both of these single-joint loads. Furthermore, changes in activity of individual neurons during multi-joint loads could be predicted from their response to subordinate single-joint loads. These findings suggest that neural representations of different mechanical contexts in MI are organized in a highly structured manner that may provide a neural basis for how complex motor behaviour is learned from simpler motor tasks.