Yamazaki Yudai, Sato Daisuke, Yamashiro Koya, Nakano Saki, Onishi Hideaki, Maruyama Atsuo
Major in Health and Welfare, Niigata University of Health and Welfare, Niigata, Japan.
Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.
Front Physiol. 2019 Nov 7;10:1361. doi: 10.3389/fphys.2019.01361. eCollection 2019.
Recent studies have reported that acute aerobic exercise modulates intracortical excitability in the primary motor cortex (M1). However, whether acute low-intensity aerobic exercise can also modulate M1 intracortical excitability, particularly intracortical excitatory circuits, remains unclear. In addition, no previous studies have investigated the effect of acute aerobic exercise on short-latency afferent inhibition (SAI). The aim of this study was to investigate whether acute low-intensity aerobic exercise modulates intracortical circuits in the M1 hand and leg areas. Intracortical excitability of M1 (Experiments 1, 2) and spinal excitability (Experiment 3) were measured before and after acute low-intensity aerobic exercise. In Experiment 3, skin temperature was also measured throughout the experiment. Transcranial magnetic stimulation was applied over the M1 non-exercised hand and exercised leg areas in Experiments 1, 2, respectively. Participants performed 30 min of low-intensity pedaling exercise or rested while sitting on the ergometer. Short- and long-interval intracortical inhibition (SICI and LICI), and SAI were measured to assess M1 inhibitory circuits. Intracortical facilitation (ICF) and short-interval intracortical facilitation (SICF) were measured to assess M1 excitatory circuits. We found that acute low-intensity aerobic exercise decreased SICI and SAI in the M1 hand and leg areas. After exercise, ICF in the M1 hand area was lower than in the control experiment, but was not significantly different to baseline. The single motor-evoked potential, resting motor threshold, LICI, SICF, and spinal excitability did not change following exercise. In conclusion, acute low-intensity pedaling modulates M1 intracortical circuits of both exercised and non-exercised areas, without affecting corticospinal and spinal excitability.
近期研究报告称，急性有氧运动可调节初级运动皮层（M1）的皮质内兴奋性。然而，急性低强度有氧运动是否也能调节M1皮质内兴奋性，尤其是皮质内兴奋性回路，仍不清楚。此外，以往尚无研究调查急性有氧运动对短潜伏期传入抑制（SAI）的影响。本研究的目的是调查急性低强度有氧运动是否能调节M1手部和腿部区域的皮质内回路。在急性低强度有氧运动前后，测量了M1的皮质内兴奋性（实验1、2）和脊髓兴奋性（实验3）。在实验3中，还在整个实验过程中测量了皮肤温度。在实验1、2中，分别在M1未运动的手部区域和运动的腿部区域施加经颅磁刺激。参与者进行了30分钟的低强度蹬车运动或坐在测力计上休息。测量短间隔和长间隔皮质内抑制（SICI和LICI）以及SAI，以评估M1抑制性回路。测量皮质内易化（ICF）和短间隔皮质内易化（SICF），以评估M1兴奋性回路。我们发现，急性低强度有氧运动降低了M1手部和腿部区域的SICI和SAI。运动后，M1手部区域的ICF低于对照实验，但与基线无显著差异。单次运动诱发电位、静息运动阈值、LICI、SICF和脊髓兴奋性在运动后未发生变化。总之，急性低强度蹬车运动可调节运动和未运动区域的M1皮质内回路，而不影响皮质脊髓和脊髓兴奋性。
