Nonlinear cortical modulation of muscle fatigue: a functional MRI study
Nonlinear cortical modulation of muscle fatigue: a functional MRI study
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DOI：
10.1016/s0006-8993(02)03665-x
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发表时间：
2002-12-13
期刊：
影响因子：
2.9
通讯作者：
Yue, GH
中科院分区：
文献类型：
--
作者：
Liu, JZ;Dai, TH;Yue, GH
肌肉疲劳的研究已经有一个多世纪了，但几乎没有数据可以表明大脑如何感知疲劳并调节其向疲劳肌肉发出的信号。在这项研究中，通过功能磁共振成像（fMRl）测量持续（2分钟）最大努力握力收缩期间的大脑激活，同时通过磁共振环境适应力肌电图测量系统同时记录握力和手指肌肉肌电图（EMG）数据。结果显示，当肌肉疲劳时，大脑和肌肉活动的进展呈脱钩状态，并且所分析的皮质区域之间存在相关行为。虽然在肌肉疲劳过程中，握力和肌电图信号同时下降，但功能磁共振成像测量的大脑活动首先大幅增加，然后减少。这种类似的信号调制不仅发生在初级感觉运动区域，而且也发生在次级和联合皮质（辅助运动、前额叶和扣带回区域）。非线性变化。大脑信号的变化可能反映了早期的调整，以加强力损失补偿的下降命令，以及随着疲劳变得更加严重而随后通过感觉反馈进行的抑制。许多皮质区域的激活模式的密切关联可能反映了大脑中信息的综合处理。 (C) 2002 Elsevier Science B.V. 保留所有权利。
Muscle fatigue has been studied for over a century, but almost no data are available to indicate how the brain perceives fatigue and modulates its signals to the fatiguing muscle. In this study, brain activation was measured by functional magnetic resonance imaging (fMRl) during a sustained (2-min) maximal-effort handgrip contraction while handgrip force and finger muscle electromyographic (EMG) data were recorded simultaneously by a magnetic resonance environment-adapted force-EMG measurement system. The results showed decoupled progresses in brain and muscle activities when muscle was fatigued and correlated behaviors among the cortical areas being analyzed. While handgrip force and EMG signals declined in parallel during the course of muscle fatigue, fMRI-measured brain activities first substantially increased and then decreased. This similar signal modulation occurred not only in the primary sensorimotor areas but also in the secondary and association cortices (supplementary motor, prefrontal, and cingulate areas). The nonlinear changes. of brain signal may reflect an early adjustment to strengthen the descending command for force-loss compensation and subsequent inhibition by sensory feedback as fatigue became more severe. The close association in the activation pattern in many cortical regions may reflect integrated processing of information in the brain. (C) 2002 Elsevier Science B.V. All rights reserved.