Jiang Yu, Chen Yuan, Zheng Ruiping, Zhou Bingqian, Wei Ying, Gao Ankang, Wei Yarui, Li Shuying, Guo Jinxia, Han Shaoqiang, Zhang Yong, Cheng Jingliang
Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China.
Front Hum Neurosci. 2022 Apr 8;16:868135. doi: 10.3389/fnhum.2022.868135. eCollection 2022.
Several functional magnetic resonance imaging (fMRI) studies have demonstrated abnormalities in static intra- and interhemispheric functional connectivity among diverse brain regions in patients with major depressive disorder (MDD). However, the dynamic changes in intra- and interhemispheric functional connectivity patterns in patients with MDD remain unclear. Fifty-eight first-episode, drug-naive patients with MDD and 48 age-, sex-, and education level-matched healthy controls (HCs) underwent resting-state fMRI. Whole-brain functional connectivity, analyzed using the functional connectivity density (FCD) approach, was decomposed into ipsilateral and contralateral functional connectivity. We computed the intra- and interhemispheric dynamic FCD (dFCD) using a sliding window analysis to capture the dynamic patterns of functional connectivity. The temporal variability in functional connectivity was quantified as the variance of the dFCD over time. In addition, intra- and interhemispheric static FCD (sFCD) patterns were calculated. Associations between the dFCD variance and sFCD in abnormal brain regions and the severity of depressive symptoms were analyzed. Compared to HCs, patients with MDD showed lower interhemispheric dFCD variability in the inferior/middle frontal gyrus and decreased sFCD in the medial prefrontal cortex/anterior cingulate cortex and posterior cingulate cortex/precuneus in both intra- and interhemispheric comparisons. No significant correlations were found between any abnormal dFCD variance or sFCD at the intra- and interhemispheric levels and the severity of depressive symptoms. Our results suggest intra- and interhemispheric functional connectivity alterations in the dorsolateral prefrontal cortex (DLPFC) and default mode network regions involved in cognition, execution and emotion. Furthermore, our study emphasizes the essential role of altered interhemispheric communication dynamics in the DLPFC in patients with MDD. These findings contribute to our understanding of the pathophysiology of MDD.
多项功能磁共振成像（fMRI）研究表明，重度抑郁症（MDD）患者不同脑区之间的静态半球内和半球间功能连接存在异常。然而，MDD患者半球内和半球间功能连接模式的动态变化仍不清楚。58名首发、未接受过药物治疗的MDD患者和48名年龄、性别和教育水平相匹配的健康对照者（HCs）接受了静息态fMRI检查。使用功能连接密度（FCD）方法分析的全脑功能连接被分解为同侧和对侧功能连接。我们使用滑动窗口分析计算半球内和半球间动态FCD（dFCD），以捕捉功能连接的动态模式。功能连接的时间变异性被量化为dFCD随时间的方差。此外，还计算了半球内和半球间静态FCD（sFCD）模式。分析了异常脑区dFCD方差和sFCD与抑郁症状严重程度之间的关联。与HCs相比，MDD患者在额下回/额中回的半球间dFCD变异性较低，在半球内和半球间比较中，内侧前额叶皮质/前扣带回皮质以及后扣带回皮质/楔前叶的sFCD均降低。在半球内和半球间水平上，任何异常的dFCD方差或sFCD与抑郁症状严重程度之间均未发现显著相关性。我们的结果表明，背外侧前额叶皮质（DLPFC）以及参与认知、执行和情感的默认模式网络区域存在半球内和半球间功能连接改变。此外，我们的研究强调了DLPFC中半球间交流动态改变在MDD患者中的重要作用。这些发现有助于我们理解MDD的病理生理学。
