Sasaki Ryoki, Miyaguchi Shota, Kotan Shinichi, Kojima Sho, Kirimoto Hikari, Onishi Hideaki
Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan.
Front Hum Neurosci. 2016 Feb 4;10:30. doi: 10.3389/fnhum.2016.00030. eCollection 2016.
Here, we aimed to evaluate whether cathodal transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) and primary somatosensory cortex (S1) can modulate cortical inhibitory circuits. Sixteen healthy subjects participated in this study. Cathodal tDCS was positioned over the left M1 (M1 cathodal) or left S1 (S1 cathodal) with an intensity of 1 mA for 10 min. Sham tDCS was applied for 10 min over the left M1 (sham). Motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) were recorded from the right abductor pollicis brevis (APB) muscle before the intervention (pre) and 10 and 30 min after the intervention (post 1 and post 2, respectively). Cortical inhibitory circuits were evaluated using short-interval intracortical inhibition (SICI) and short-latency afferent inhibition (SAI). M1 cathodal decreased single-pulse MEP amplitudes at post 1 and decreased SAI at post 1 and post 2; however, SICI did not exhibit any change. S1 cathodal and sham did not show any changes in MEP amplitudes at any of the three time points. These results demonstrated that cathodal tDCS over the M1 not only decreases the M1 excitability but also affects the cortical inhibitory circuits related to SAI.
在此，我们旨在评估经颅直流电刺激（tDCS）阴极刺激初级运动皮层（M1）和初级体感皮层（S1）是否能够调节皮层抑制性回路。16名健康受试者参与了本研究。将tDCS阴极置于左侧M1（M1阴极组）或左侧S1（S1阴极组），强度为1 mA，持续10分钟。在左侧M1施加假tDCS 10分钟（假刺激组）。在干预前（预）以及干预后10分钟和30分钟（分别为后1和后2），从右侧拇短展肌（APB）记录经颅磁刺激（TMS）诱发的运动诱发电位（MEP）。使用短间隔皮层内抑制（SICI）和短潜伏期传入抑制（SAI）评估皮层抑制性回路。M1阴极组在干预后1时单脉冲MEP波幅降低，在干预后1和干预后2时SAI降低；然而，SICI未表现出任何变化。S1阴极组和假刺激组在三个时间点中的任何一个时间点MEP波幅均未显示任何变化。这些结果表明，M1上的阴极tDCS不仅降低了M1的兴奋性，还影响了与SAI相关的皮层抑制性回路。
