Characterising stationary and dynamic effective connectivity changes in the motor network during and after tDCS.
Characterising stationary and dynamic effective connectivity changes in the motor network during and after tDCS.
复制标题
表征 tDCS 期间和之后运动网络的静态和动态有效连接变化。
DOI：
10.1016/j.neuroimage.2023.119915
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发表时间：
2023
期刊：
影响因子：
5.7
通讯作者：
Calzolari S
中科院分区：
文献类型：
--
作者：
Calzolari S
经颅直流电刺激（tDCS）在网络水平上的作用背后的确切机制仍然知之甚少，迄今为止，大多数研究都集中在局部（皮层）效应和运动诱发电位或BOLD信号的变化上。在这里，我们探讨了静态和动态的有效连接在运动网络在休息时，在两个实验中，我们分别应用tDCS在初级运动皮层（M1-tDCS）或小脑（CB-tDCS）。两组健康志愿者（n= 21和n = 22）在20分钟的静息状态功能性磁共振成像（fMRI）期间接受阳极、阴极和假tDCS（平衡）。我们使用频谱动态因果模型（DCM）和分层参数经验贝叶斯（PEB）来分析刺激后（与tDCS前基线相比）和刺激期间的数据。我们还实现了一种新的动态（滑动窗口）DCM/PEB方法来模拟网络重组的性质。在这两个实验中，我们发现tDCS的广泛影响超出了目标区域，并调制了皮层，丘脑和小脑之间的有效连接。这些变化的特点是独特的非线性时间指纹连接和极性。我们的研究结果支持越来越多的研究挑战的经典概念的阳极和阴极tDCS的兴奋性和抑制性分别，以及随着时间的推移tDCS的累积效应的想法。相反，它们描述了一系列具有特定空间和时间模式的丰富变化。我们的工作为推进我们对网络水平tDCS效应的理解提供了一个起点，并可能指导未来的工作，以优化其认知和临床应用。
The exact mechanisms behind the effects of transcranial direct current stimulation (tDCS) at a network level are still poorly understood, with most studies to date focusing on local (cortical) effects and changes in motor-evoked potentials or BOLD signal. Here, we explored stationary and dynamic effective connectivity across the motor network at rest in two experiments where we applied tDCS over the primary motor cortex (M1-tDCS) or the cerebellum (cb-tDCS) respectively. Two cohorts of healthy volunteers (n= 21 andn= 22) received anodal, cathodal, and sham tDCS sessions (counterbalanced) during 20 min of resting-state functional magnetic resonance imaging (fMRI). We used spectral Dynamic Causal Modelling (DCM) and hierarchical Parametrical Empirical Bayes (PEB) to analyze data after (compared to a pre-tDCS baseline) and during stimulation. We also implemented a novel dynamic (sliding windows) DCM/PEB approach to model the nature of network reorganisation across time. In both experiments we found widespread effects of tDCS that extended beyond the targeted area and modulated effective connectivity between cortex, thalamus, and cerebellum. These changes were characterised by unique nonlinear temporal fingerprints across connections and polarities. Our results support growing research challenging the classic notion of anodal and cathodal tDCS as excitatory and inhibitory respectively, as well as the idea of a cumulative effect of tDCS over time. Instead, they described a rich set of changes with specific spatial and temporal patterns. Our work provides a starting point for advancing our understanding of network-level tDCS effects and may guide future work to optimise its cognitive and clinical applications.