Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Movement Disorders and Neurostimulation, Department of Neurology, Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
Neuroimage. 2024 Sep;298:120774. doi: 10.1016/j.neuroimage.2024.120774. Epub 2024 Aug 3.
How cortical oscillations are involved in the coordination of functionally coupled muscles and how this is modulated by different movement contexts (static vs dynamic) remains unclear. Here, this is investigated by recording high-density electroencephalography (EEG) and electromyography (EMG) from different forearm muscles while healthy participants (n = 20) performed movement tasks (static and dynamic posture holding, and reaching) with their dominant hand. When dynamic perturbation was applied, beta band (15-35 Hz) activities in the motor cortex contralateral to the performing hand reduced during the holding phase, comparative to when there was no perturbation. During static posture holding, transient periods of increased cortical beta oscillations (beta bursts) were associated with greater corticomuscular coherence and increased phase synchrony between muscles (intermuscular coherence) in the beta frequency band compared to the no-burst period. This effect was not present when resisting dynamic perturbation. The results suggest that cortical beta bursts assist synchronisation of different muscles during static posture holding in healthy motor control, contributing to the maintenance and stabilisation of functional muscle groups. Theoretically, increased cortical beta oscillations could lead to exaggerated synchronisation in different muscles making the initialisation of movements more difficult, as observed in Parkinson's disease.
皮层振荡如何参与功能耦合肌肉的协调，以及不同运动情境（静态与动态）如何对此进行调节仍不清楚。本研究通过记录健康参与者（n=20）使用惯用手进行运动任务（静态和动态姿势保持以及伸手）时不同前臂肌肉的高密度脑电图（EEG）和肌电图（EMG），来对此进行研究。当施加动态干扰时，与没有干扰时相比，运动皮层中与执行手相对侧的β频带（15-35 Hz）活动在保持阶段减少。在静态姿势保持期间，与无突发期相比，皮质β频带中短暂的皮质β振荡（β爆发）增加与更大的皮质肌相干性和肌肉之间（肌肉间相干性）的相位同步性增加有关。当抵抗动态干扰时，这种效果不存在。结果表明，在健康运动控制中，皮质β爆发有助于在静态姿势保持期间不同肌肉的同步，有助于维持和稳定功能肌肉群。从理论上讲，增加的皮质β振荡可能导致不同肌肉的过度同步，从而使运动的初始化更加困难，如在帕金森病中观察到的那样。
