The Temporal Dynamics of EEG Microstate Reveals the Neuromodulation Effect of Acupuncture With Deqi.

The electroencephalography (EEG) microstate has recently emerged as a new whole-brain mapping tool for studying the temporal dynamics of the human brain. Meanwhile, the neuromodulation effect of external stimulation on the human brain is of increasing interest to neuroscientists. Acupuncture, which originated in ancient China, is recognized as an external neuromodulation method with therapeutic effects. Effective acupuncture could elicit the deqi effect, which is a combination of multiple sensations. However, whether the EEG microstate could be used to reveal the neuromodulation effect of acupuncture with deqi remains largely unclear. In this study, multichannel EEG data were recorded from 16 healthy subjects during acupuncture manipulation, as well as during pre- and post-manipulation tactile controls and pre- and post-acupuncture rest controls. As the basic acupuncture unit for regulating the central nervous system, the Hegu acupoint was used in this study, and each subject’s acupuncture deqi behavior scores were collected. To reveal the neuroimaging evidence of acupuncture with deqi, EEG microstate analysis was conducted to obtain the microstate maps and microstate parameters for different conditions. Furthermore, Pearson’s correlation was analyzed to investigate the correlation relationship between microstate parameters and deqi behavioral scores. Results showed that: (1) compared with tactile controls, acupuncture manipulation caused significantly increased deqi behavioral scores. (2) Acupuncture manipulation significantly increased the duration, occurrence, and contribution parameters of microstate C, whereas it decreased those parameters of microstate D. (3) Microstate C’s duration parameter showed a significantly positive correlation with acupuncture deqi behavior scores. (4) Acupuncture manipulation significantly increased the transition probabilities with microstate C as node, whereas it reduced the transition probabilities with microstate D as node. (5) Microstate B→C’s transition probability also showed a significantly positive correlation with acupuncture deqi behavior scores. Taken together, the temporal dynamic feature of EEG microstate could be used as objective neuroimaging evidence to reveal the neuromodulation effect of acupuncture with deqi.

脑电图（EEG）微状态最近已成为一种研究人类大脑时间动态的全新全脑映射工具。同时，外部刺激对人脑的神经调节作用越来越受到神经科学家的关注。起源于古代中国的针灸被认为是一种具有治疗效果的外部神经调节方法。有效的针灸能够引发得气效应，这是多种感觉的组合。然而，脑电图微状态是否可用于揭示伴有得气的针灸的神经调节作用在很大程度上仍不清楚。在本研究中，对16名健康受试者在针灸操作过程中以及操作前后的触觉对照和针灸前后的静息对照期间记录了多通道脑电图数据。作为调节中枢神经系统的基本针灸穴位，本研究使用了合谷穴，并收集了每位受试者的针灸得气行为评分。为了揭示伴有得气的针灸的神经影像学证据，进行了脑电图微状态分析以获得不同条件下的微状态图和微状态参数。此外，还分析了皮尔逊相关性以研究微状态参数与得气行为评分之间的相关关系。结果显示：（1）与触觉对照相比，针灸操作导致得气行为评分显著提高。（2）针灸操作显著增加了微状态C的持续时间、出现次数和贡献率参数，而降低了微状态D的这些参数。（3）微状态C的持续时间参数与针灸得气行为评分呈显著正相关。（4）针灸操作显著增加了以微状态C为节点的转换概率，而降低了以微状态D为节点的转换概率。（5）微状态B→C的转换概率也与针灸得气行为评分呈显著正相关。综上所述，脑电图微状态的时间动态特征可作为客观的神经影像学证据来揭示伴有得气的针灸的神经调节作用。