Tingting Lei, Lilin Chen, Chuangjia Wang, Jiamen Si, Shuxian Zhang, Yinan Ai, Hanjun Liu, Haiqing Zheng
Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China.
Department of Cardiovascular Medicine, Xi'an Central Hospital, Xi'an, Shanxi, China.
J Neuroeng Rehabil. 2025 Mar 27;22(1):69. doi: 10.1186/s12984-025-01610-2.
Transcranial alternating current stimulation (tACS) is a non-invasive technique that modulates neural oscillations, yet its specific effects on cortical excitability are not well-understood. This study investigated the effects of tACS on neuroplasticity in the primary motor cortex (M1) across different frequencies.
In this randomized, sham-controlled, crossover study, 18 healthy young adults received β-tACS γ-tACS, and sham stimulation over the M1. Neurophysiological responses were assessed using motor evoked potentials (MEPs), electroencephalograms (EEG), and transcranial evoked potentials (TEPs) to determine the frequency-specific effects of tACS on cortical excitability and neuroplasticity.
γ-tACS significantly enhanced cortical excitability, as reflected by larger MEP amplitudes compared to both β-tACS and sham stimulation. In addition, γ-tACS resulted in significantly smaller M1-P15 amplitudes in TEP than other stimulation conditions. In contrast, β-tACS did not produce significant changes in either MEPs or TEPs compared to sham stimulation.
These findings provide evidence that tACS induces frequency-dependent effects on cortical excitability and neuroplasticity within the M1. This selective modulation of cortical excitability with γ-tACS suggests its potential as a therapeutic intervention for optimizing motor function and rehabilitation.
This study was registered in the Chinese Clinical Trial Registry (ChiCTR2300074898, date of registration: 2023/08/18).
经颅交流电刺激（tACS）是一种调节神经振荡的非侵入性技术，但其对皮质兴奋性的具体影响尚未完全明确。本研究调查了不同频率的tACS对初级运动皮层（M1）神经可塑性的影响。
在这项随机、假刺激对照、交叉研究中，18名健康年轻成年人在M1区域接受了β-tACS、γ-tACS和假刺激。使用运动诱发电位（MEP）、脑电图（EEG）和经颅诱发电位（TEP）评估神经生理反应，以确定tACS对皮质兴奋性和神经可塑性的频率特异性影响。
与β-tACS和假刺激相比，γ-tACS显著增强了皮质兴奋性，表现为MEP波幅更大。此外，与其他刺激条件相比，γ-tACS导致TEP中M1-P15波幅显著更小。相比之下，与假刺激相比，β-tACS在MEP或TEP上均未产生显著变化。
这些发现提供了证据，表明tACS对M1内的皮质兴奋性和神经可塑性具有频率依赖性影响。γ-tACS对皮质兴奋性的这种选择性调节表明其作为优化运动功能和康复的治疗干预措施的潜力。
本研究在中国临床试验注册中心注册（ChiCTR2300074898，注册日期：2023/08/18）。
