Department of Oral Implantology, School of Stomatology, Capital Medical University, Dongcheng District, Beijing 100050, PR China.
Arch Oral Biol. 2013 Oct;58(10):1483-90. doi: 10.1016/j.archoralbio.2013.06.012. Epub 2013 Jul 11.
Transcranial magnetic stimulation (TMS) has been used to assess corticomotor control of jaw muscles, but few studies have examined cortical plasticity of the masticatory system and potential modification by jaw muscle training.
To determine if a 1-h jaw muscle training task would be sufficient to induce signs of neuroplastic changes in the corticomotor excitability of the masseter muscle.
Corticomotor excitability was assessed by changes in electromyographic activity evoked by TMS in 15 healthy participants. Motor evoked potentials (MEPs) recorded in the masseter and the first dorsal interosseos (FDI - as a control) muscle were assessed at four time points: at baseline, immediately after the 1-h training, 1h after training and 1 day follow-up (n=7). MEPs were assessed by stimulus-response curves and corticomotor mapping.
All participants successfully performed the task (mean success rate: 47.0±4.1%) which increased significantly during the 1-h training. However, no significant effect of jaw muscle training on masseter and FDI MEPs or corticomotor maps were observed.
The present finding showed that 1-h jaw muscle training is insufficient to evoke neuroplastic changes in corticomotor excitability. The potential for training-induced neuroplasticity may vary among different cranial muscles which may have therapeutic consequences.
经颅磁刺激（TMS）已被用于评估咀嚼肌的皮质运动控制，但很少有研究探讨咀嚼系统的皮质可塑性以及咀嚼肌训练的潜在改变。
确定 1 小时的咀嚼肌训练任务是否足以引起咬肌皮质运动兴奋性的神经可塑性变化的迹象。
通过 TMS 在 15 名健康参与者中诱发的肌电图活动变化来评估皮质运动兴奋性。在四个时间点评估记录在咬肌和第一背间骨间肌（FDI-作为对照）中的运动诱发电位（MEP）：基线时、1 小时训练后、训练后 1 小时和 1 天随访时（n=7）。通过刺激反应曲线和皮质运动映射评估 MEP。
所有参与者均成功完成任务（平均成功率：47.0±4.1%），在 1 小时的训练中显著增加。然而，咀嚼肌训练对咬肌和 FDI MEP 或皮质运动映射没有显著影响。
本研究结果表明，1 小时的咀嚼肌训练不足以引起皮质运动兴奋性的神经可塑性变化。训练诱导的神经可塑性的潜力可能因不同的颅面肌肉而异，这可能具有治疗意义。
