Central resetting of neuromuscular steady states may underlie rhythmical arm movements
Central resetting of neuromuscular steady states may underlie rhythmical arm movements
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DOI：
10.1152/jn.01152.2005
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发表时间：
2006-09-01
影响因子：
2.5
通讯作者：
Levin, Mindy F.
中科院分区：
文献类型：
--
作者：
Ustinova, Ksenia I.;Feldman, Anatol G.;Levin, Mindy F.
改变身体或其部分的稳态配置可能是运动和其他节律运动的中枢模式发生器的重要功能。因此，肌肉激活、力和运动可以按照神经肌肉系统的自然趋势出现，以实现当前的稳态配置。为了验证有节奏的运动过程中不同稳态之间的转变，我们要求站立的受试者从肩关节以大约 0.8 Hz 的频率同步或往复摆动一只或两只手臂。在随机选择的周期中，一只手臂被电磁装置暂时阻止。经过一段延迟和相位重置后，摆动恢复。在双边摆动期间，未受扰动的手臂经常停止，然后在接近扰动之前观察到的最向前或最向后的手臂位置的位置恢复摆动。当最初产生同步双边模式时，当双臂到达相似的极限位置时，或者如果初始模式是相互的，则当双臂到达相反的位置时，通常会恢复振荡。结果表明，中央发生器通过在其稳态（平衡）位置之间产生转变来控制双臂作为一个连贯单元。通过控制这些位置，系统可以定义运动的空间边界。在这些位置，系统可能会停止振荡，在新的阶段恢复振荡（如本研究中观察到的），或启动新的运动动作。我们的研究结果与运动相关，表明行走也可能是由身体的几种平衡配置之间的转变产生的，这可能是通过本体感觉反射的调节和门控来实现的。
Changing the steady-state configuration of the body or its segments may be an important function of central pattern generators for locomotion and other rhythmical movements. Thereby, muscle activation, forces, and movement may emerge following a natural tendency of the neuromuscular system to achieve the current steady-state configuration. To verify that transitions between different steady states occur during rhythmical movements, we asked standing subjects to swing one or both arms synchronously or reciprocally at similar to 0.8 Hz from the shoulder joints. In randomly selected cycles, one arm was transiently arrested by an electromagnetic device. Swinging resumed after some delay and phase resetting. During bilateral swinging, the nonperturbed arm often stopped before resuming swinging at a position that was close to either the extreme forward or the extreme backward arm position observed before the perturbation. Oscillations usually resumed when both arms arrived at similar extreme positions when a synchronous bilateral pattern was initially produced or at the opposite positions if the initial pattern was reciprocal. Results suggest that a central generator controls both arms as a coherent unit by producing transitions between its steady state (equilibrium) positions. By controlling these positions, the system may define the spatial boundaries of movement. At these positions, the system may halt the oscillations, resume them at a new phase (as observed in the present study), or initiate a new motor action. Our findings are relevant to locomotion and suggest that walking may also be generated by transitions between several equilibrium configurations of the body, possibly accomplished by modulation and gating of proprioceptive reflexes.