State-Dependent Effects of Transcranial Oscillatory Currents on the Motor System: What You Think Matters
State-Dependent Effects of Transcranial Oscillatory Currents on the Motor System: What You Think Matters
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DOI：
10.1523/jneurosci.1414-13.2013
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发表时间：
2013-10-30
影响因子：
5.3
通讯作者：
Rossi, Simone
中科院分区：
文献类型：
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作者：
Feurra, Matteo;Pasqualetti, Patrizio;Rossi, Simone
无知觉经颅交流电刺激（tACS）以频率特异性方式改变内源性皮层振荡活动。在人类运动系统中，tACS与静止运动皮质的空转β节律一致，增加了皮质脊髓输出。我们推断，改变大脑的初始状态（即，从静止到使局部β节律去兴奋的运动想象任务）也可能改变皮质脊髓系统对β-tACS诱导的共振效应的易感性。我们通过在休息时和运动想象期间在初级运动皮层上以不同频率（θ，α，β和γ）传递tACS来测试这一假设。运动诱发电位（MEP）是通过经颅磁刺激（TMS）在初级运动皮层与在线导航TMS-tACS设置。在运动想象过程中，皮质脊髓兴奋性的增加是最大的theta-tACS，可能反映了精神处理和“执行”认知任务所需的工作记忆过程的加强。正如预期的那样，受试者在休息时的最大MEP增加是用β-tACS获得的，证实了先前的证据。这种分离提供了新的证据的状态和频率依赖性的tACS对运动系统的影响，并有助于辨别不同的振荡频率的大脑区域的功能作用。这些发现可能与康复神经调节干预有关。
Imperceptible transcranial alternating current stimulation (tACS) changes the endogenous cortical oscillatory activity in a frequency-specific manner. In the human motor system, tACS coincident with the idling beta rhythm of the quiescent motor cortex increased the corticospinal output. We reasoned that changing the initial state of the brain (i.e., from quiescence to a motor imagery task that desynchronizes the local beta rhythm) might also change the susceptibility of the corticospinal system to resonance effects induced by beta-tACS. We tested this hypothesis by delivering tACS at different frequencies (theta, alpha, beta, and gamma) on the primary motor cortex at rest and during motor imagery. Motor-evoked potentials (MEPs) were obtained by transcranial magnetic stimulation (TMS) on the primary motor cortex with an online-navigated TMS-tACS setting. During motor imagery, the increase of corticospinal excitability was maximal with theta-tACS, likely reflecting a reinforcement of working memory processes required to mentally process and "execute" the cognitive task. As expected, the maximal MEPs increase with subjects at rest was instead obtained with beta-tACS, substantiating previous evidence. This dissociation provides new evidence of state and frequency dependency of tACS effects on the motor system and helps discern the functional role of different oscillatory frequencies of this brain region. These findings may be relevant for rehabilitative neuromodulatory interventions.