Brasil-Neto J P, Pascual-Leone A, Valls-Solé J, Cammarota A, Cohen L G, Hallett M
Human Cortical Physiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Exp Brain Res. 1993;93(1):181-4. doi: 10.1007/BF00227794.
Fatigue of voluntary muscular effort is a complex and multifaceted phenomenon. Fatigue of peripheral nervous system components, including the contractile apparatus and the neuromuscular junction, has been well studied. Central nervous system components also fatigue, but studies have lagged for want of objective methods. Transcranial magnetic stimulation is a relatively new technique that can be used to assess central nervous system excitability from the motor cortex to the alpha-motoneuron. In six normal volunteers, including four of the investigators, the amplitudes of motor evoked potentials elicited by transcranial magnetic stimulation were transiently decreased after exercise, indicating fatigue of motor pathways in the central nervous system. The decrease in amplitude was associated with a feeling of fatigue. The mechanism of this phenomenon is apparently decreased efficiency in the generation of the motor command in the motor cortex.
随意肌肉运动的疲劳是一种复杂且多方面的现象。包括收缩装置和神经肌肉接头在内的外周神经系统成分的疲劳已得到充分研究。中枢神经系统成分也会疲劳，但由于缺乏客观方法，相关研究滞后。经颅磁刺激是一种相对较新的技术，可用于评估从运动皮层到α运动神经元的中枢神经系统兴奋性。在六名正常志愿者（包括四名研究者）中，经颅磁刺激诱发的运动诱发电位幅度在运动后短暂降低，表明中枢神经系统运动通路出现疲劳。幅度降低与疲劳感相关。这种现象的机制显然是运动皮层中运动指令生成效率降低。
