Effects of 10Hz and 20Hz transcranial alternating current stimulation (tACS) on motor functions and motor cortical excitability
Effects of 10Hz and 20Hz transcranial alternating current stimulation (tACS) on motor functions and motor cortical excitability
复制标题
DOI：
10.1016/j.bbr.2012.11.038
复制
发表时间：
2013-03
影响因子：
2.7
通讯作者：
C. Wach;V. Krause;V. Moliadze;W. Paulus;A. Schnitzler;B. Pollok
中科院分区：
文献类型：
--
作者：
C. Wach;V. Krause;V. Moliadze;W. Paulus;A. Schnitzler;B. Pollok
α (8-12Hz)和β (13-30Hz)频率的同步振荡活动在电机控制中起关键作用。然而，其确切的功能意义尚未得到解决。经颅交流电刺激（tACS）允许频率特异性调制正在进行的振荡活动。本研究的目的是探讨10和20Hz的tACS对健康受试者左初级运动皮层（M1）运动功能和皮层兴奋性的影响。为此，应用tACS 10min。假性刺激作为对照组。对15名右撇子受试者在M1运动前后（0、30、60min）的运动速度和准确性进行评估。皮质沉默期（CSP）和运动诱发电位（MEPs）作为M1兴奋性的测量。10Hz的tACS会增加运动的可变性，尤其是在需要内部起搏的任务中，而20Hz的tACS会导致运动变慢。行为效应发生在不同的时间窗口。10Hz效应在刺激后30分钟内出现，而20Hz的tACS效应在刺激后立即出现。在10Hz的tACS下，这些效应与CSP持续时间显著相关，表明抑制通路受到干扰。目前的研究结果表明，刺激频率对运动行为和M1兴奋性的不同影响。
Synchronized oscillatory activity at alpha (8–12Hz) and beta (13–30Hz) frequencies plays a key role in motor control. Nevertheless, its exact functional significance has yet to be solved. Transcranial alternating current stimulation (tACS) allows the frequency-specific modulation of ongoing oscillatory activity. The goal of the present study was to investigate the effect of 10 and 20Hz tACS over left primary motor cortex (M1) on motor functions and cortical excitability in healthy subjects. To this end, tACS was applied for 10min. Sham stimulation served as control condition. Movement speed and accuracy of the right hand were assessed in 15 right-handed subjects before and after (0, 30 and 60min) tACS of M1. Cortical silent period (CSP) and motor evoked potentials (MEPs) were determined as measures of M1 excitability. While 10Hz tACS particularly increased movement variability, especially in tasks requiring internal pacing, 20Hz tACS resulted in movement slowing. Behavioural effects occurred in distinct time windows. While 10Hz effects developed over 30min after stimulation, 20Hz tACS effects were found immediately after stimulation. Following 10Hz tACS these effects were significantly correlated with CSP duration, indicating interference with inhibitory pathways. The present findings suggest differential effects of stimulation frequency on motor behaviour and M1 excitability.