School of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.
The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou 510370, China.
J Affect Disord. 2019 Jun 15;253:18-25. doi: 10.1016/j.jad.2019.04.040. Epub 2019 Apr 8.
Many previous studies have revealed abnormal functional connectivity patterns between brain areas underlying the onset of major depressive disorder (MDD) using resting-state functional magnetic resonance imaging (rs-fMRI). However, how to exactly characterize the voxel-wise whole brain functional connectivity pattern changes in MDD remains unclear, which will provide more convincing evidence for localizing the exactly functional connectivity abnormality in MDD.
In this study, we employed our newly developed whole brain functional connectivity homogeneity (FcHo) method to identify the voxel-wise changes of functional connectivity patterns in 27 medication-free MDD patients and 34 gender-, age-, and education level-matched healthy controls (HC). Furthermore, seed-based functional connectivity analysis was then used to identify the alteration of corresponding functional connectivity.
Significantly decreased FcHo values in right ventral anterior insula (INS) and medial prefrontal cortex (MPFC) were identified in MDD patients. The ensuing functional connectivity analyses identified decreased functional connectivity between MPFC and left angular gyrus (AG) in MDD patients. Moreover, both decreased FcHo values in INS, MPFC and functional connectivity between MPFC and left AG showed significant negative correlations with Hamilton depression rating scale (HDRS) scores. The FcHo values in INS were also negatively correlated with disease duration. Finally, meta-analysis based functional characterization found that these brain areas are mainly involved in emotion, theory of mind and reward processing.
Our findings revealed abnormal whole brain FcHo in INS and MPFC and functional interactions between MPFC and AG in MDD and suggested that dysfunctions of INS and MPFC play an important role in the neuropathology of MDD.
许多先前的研究已经通过静息态功能磁共振成像(rs-fMRI)揭示了导致重度抑郁症（MDD）的大脑区域之间异常的功能连接模式。然而，如何准确地描述 MDD 患者全脑功能连接模式的变化仍然不清楚，这将为定位 MDD 中的确切功能连接异常提供更有说服力的证据。
在这项研究中，我们采用了我们新开发的全脑功能连接同质性（FcHo）方法，以识别 27 名未用药的 MDD 患者和 34 名性别、年龄和教育水平匹配的健康对照者（HC）的全脑功能连接模式的体素变化。此外，然后使用基于种子的功能连接分析来识别相应功能连接的变化。
在 MDD 患者中，右侧腹侧前岛叶（INS）和内侧前额叶皮层（MPFC）的 FcHo 值显著降低。随后的功能连接分析发现 MDD 患者的 MPFC 与左角回（AG）之间的功能连接减少。此外，INS 和 MPFC 的 FcHo 值降低以及 MPFC 与左 AG 之间的功能连接与汉密尔顿抑郁评定量表（HDRS）评分呈显著负相关。INS 的 FcHo 值也与疾病持续时间呈负相关。最后，基于元分析的功能特征化发现，这些脑区主要参与情绪、心理理论和奖励处理。
我们的研究结果揭示了 MDD 患者 INS 和 MPFC 全脑 FcHo 异常以及 MPFC 和 AG 之间的功能相互作用，并表明 INS 和 MPFC 的功能障碍在 MDD 的神经病理学中起着重要作用。
