Exercise affects positively on self-reported pain in musculoskeletal pain conditions possibly via top-down pain inhibitory networks. However, the role of cortical activity in these networks is unclear. The aim of the current exploratory study was to investigate the effects of acute exercise on cortical nociceptive processing and specifically the excitability in the human sensorimotor cortex. Five healthy adults (mean age 32.8 years) were recorded with a whole-head 306-channel magnetoencephalography (MEG, Elekta Neuromag® Triux™). Participant's right hand third fingertip was stimulated electrically with an intracutaneous non-magnetic copper tip electrode before and immediately after an exercise task. Stimulus intensity was set individually so that the stimulation was subjectively rated as moderately painful, 6-7 on a visual analog scale. The acute exercise task was an isometric three-minute fatiguing left hand contraction with force-level at 30% of maximum voluntary contraction. Data analysis was conducted as event-related evoked field and frequency analysis. Early cortical activations after stimulation were localized in the primary and secondary somatosensory cortices. The main result demonstrated modulation of cortical nociceptive processing in the sensorimotor cortex ∼20 Hz rhythm immediately after the acute exercise. In conclusion, acute exercise may have an effect on nociceptive processing in the sensorimotor cortex on oscillatory level. Research on cortical oscillations analyzing interaction between nociception and exercise is limited. This study presents results indicating brain oscillatory activity as a feasible research target for examining mechanisms interacting between exercise and cortical nociceptive processing.

中文翻译：

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急性运动调节感觉运动皮层〜20 Hz振荡引起的疼痛诱导的反应。

运动可能会通过自上而下的疼痛抑制网络对肌肉骨骼疼痛状况中的自我报告的疼痛产生积极影响。但是，皮质活动在这些网络中的作用尚不清楚。当前的探索性研究的目的是研究急性运动对皮质伤害感受过程的影响，尤其是人类感觉运动皮层的兴奋性。通过全头306通道磁脑电图（MEG，ElektaNeuromag®Triux™）记录了5名健康成年人（平均年龄32.8岁）。在锻炼任务之前和之后，用皮内非磁性铜尖端电极对参与者的右手第三指尖进行电刺激。单独设置刺激强度，以便在视觉模拟量表上将刺激主观评定为中等疼痛，为6-7。急性运动任务是等距三分钟疲劳左手收缩，力水平为最大自愿收缩的30％。进行数据分析作为与事件相关的诱发场和频率分析。刺激后早期的皮质激活位于主要和次要的体感皮质。主要结果表明，急性运动后立即在感觉运动皮层20 Hz的节奏中调节皮质伤害感受过程。总之，急性运动可能会在振荡水平上影响感觉运动皮层的伤害感受过程。分析痛觉和运动之间相互作用的皮质振荡的研究是有限的。