Laboratory of Psychophysiology of Individual Differences, Institute of Physiology and Basic Medicine, Novosibirsk, Russia.
Laboratory of Psychophysiology of Individual Differences, Institute of Physiology and Basic Medicine, Novosibirsk, Russia; Humanitarian Institute, Novosibirsk State University, Novosibirsk, Russia.
J Affect Disord. 2018 Aug 1;235:211-219. doi: 10.1016/j.jad.2018.04.003. Epub 2018 Apr 7.
The study of intrinsic connectivity networks, i.e., sets of brain regions that show a high degree of interconnectedness even in the absence of a task, showed that major depressive disorder (MDD) patients demonstrate an increased connectivity within the default mode network (DMN), which is active in a resting state and is implicated in self-referential processing, and a decreased connectivity in task-positive networks (TPNs), which increase their activity in attention tasks. Cortical localization of this 'dominance' of the DMN over the TPN in MDD patients is not fully understood. Besides, this effect has been investigated using fMRI and its electrophysiological underpinning is not known.
In this study, we tested the dominance hypothesis using seed-based connectivity analysis of resting-state fMRI and EEG data obtained in 41 MDD patients and 23 controls.
In MDD patients, as compared to controls, insula, pallidum/putamen, amygdala, and left dorso- and ventrolateral prefrontal cortex are more strongly connected with DMN than with TPN seeds. In EEG, all significant effects were obtained in the delta frequency band.
fMRI and EEG data were not obtained simultaneously during the same session.
In MDD patients, major emotion and attention regulation circuits are more strongly connected with DMN than with TPN implying they are more prepared to respond to internally generated self-related thoughts than to environmental challenges.
对内在连接网络的研究，即大脑区域的集合，即使在没有任务的情况下也显示出高度的连通性，表明重度抑郁症（MDD）患者在默认模式网络（DMN）内表现出更高的连通性，DMN 在静息状态下活跃，与自我参照处理有关，而在任务正性网络（TPN）中的连通性降低，在注意力任务中增加其活动。MDD 患者中 DMN 对 TPN 的这种“主导”的皮质定位尚不完全清楚。此外，已经使用 fMRI 研究了这种效应，但其电生理基础尚不清楚。
在这项研究中，我们使用静息态 fMRI 和 EEG 数据的种子连接分析来测试主导假设，该分析是在 41 名 MDD 患者和 23 名对照中获得的。
与对照组相比，MDD 患者的岛叶、苍白球/壳核、杏仁核和左侧背外侧和腹外侧前额皮质与 DMN 的连接比与 TPN 种子的连接更强。在 EEG 中，所有显著效应均在 delta 频带中获得。
fMRI 和 EEG 数据不是在同一会话中同时获得的。
在 MDD 患者中，主要的情绪和注意力调节回路与 DMN 的连接比与 TPN 的连接更强，这意味着它们对内部产生的自我相关思维的反应比对环境挑战的反应更为准备。
