Assessing cortical synchronization during transcranial direct current stimulation: A graph-theoretical analysis
Assessing cortical synchronization during transcranial direct current stimulation: A graph-theoretical analysis
复制标题
DOI：
10.1016/j.neuroimage.2016.06.003
复制
发表时间：
2016-10-01
期刊：
影响因子：
5.7
通讯作者：
Pellicciari, Maria Concetta
中科院分区：
文献类型：
--
作者：
Mancini, Matteo;Brignani, Debora;Pellicciari, Maria Concetta
经颅直流电刺激（tDCS）是一种神经调节技术，可以改变皮层兴奋性并以极性依赖的方式调节行为。尽管这种方法在神经科学领域得到了广泛的应用，但其对正在进行的局部或全局（网络水平）神经元活动的影响仍然不可预见。将tDCS与脑电描记术（EEG）相结合，提供了一种揭示tDCS诱导的皮质连接变化背后的神经元机制的方法。在这项研究中，12名健康受试者接受了在线tDCS-EEG记录（即，同时），在休息状态期间，使用19个EEG通道。该方案涉及阳极、阴极和假刺激条件，有源和参考电极分别位于左额中央区（FC 3）和右眉上方的前额。使用基于图论和同步可能性的网络模型处理数据。分析了四个频带（θ、α、β和γ）的结果图，以评估同步模式和图论测量中存在的tDCS诱导的差异。静息状态网络连接性在tDCS期间以θ和α带的极性特异性方式发生改变。对于θ波，在左半球额中央区，阳极tDCS相对于基线的同步性减弱（p < 0.05）。相比之下，在阴极tDCS期间，在α带的中央-顶叶、中央-枕叶和顶-枕叶区域上观察到半球间同步连接的显著增加（p < 0.05）。局部图形测量显示了tDCS诱导的极性特异性差异，认为修改网络活动，而不是特定的区域属性。我们的研究结果表明，在静息状态下应用tDCS调制本地同步以及在慢频带中的网络特性，以极性特定的方式。(C)2016 Elsevier Inc. All rights reserved.
Transcranial direct current stimulation (tDCS) is a neuromodulation technique that can alter cortical excitability and modulate behaviour in a polarity-dependent way. Despite the widespread use of this method in the neuroscience field, its effects on ongoing local or global (network level) neuronal activity are still not foreseeable. A way to shed light on the neuronal mechanisms underlying the cortical connectivity changes induced by tDCS is provided by the combination of tDCS with electroencephalography (EEG). In this study, twelve healthy subjects underwent online tDCS-EEG recording (i.e., simultaneous), during resting-state, using 19 EEG channels. The protocol involved anodal, cathodal and sham stimulation conditions, with the active and the reference electrodes in the left frontocentral area (FC3) and on the forehead over the right eyebrow, respectively. The data were processed using a network model, based on graph theory and the synchronization likelihood. The resulting graphs were analysed for four frequency bands (theta, alpha, beta and gamma) to evaluate the presence of tDCS-induced differences in synchronization patterns and graph theory measures. The resting state network connectivity resulted altered during tDCS, in a polarity-specific manner for theta and alpha bands. Anodal tDCS weakened synchronization with respect to the baseline over the fronto-central areas in the left hemisphere, for theta band (p < 0.05). In contrast, during cathodal tDCS a significant increase in inter-hemispheric synchronization connectivity was observed over the centro-parietal, centro-occipital and parieto-occipital areas for the alpha band (p < 0.05). Local graph measures showed a tDCS-induced polarity-specific differences that regarded modifications of network activities rather than specific region properties. Our results show that applying tDCS during the resting state modulates local synchronization as well as network properties in slow frequency bands, in a polarity-specific manner. (C) 2016 Elsevier Inc. All rights reserved.