Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
School of Psychology, Nanjing Normal University, Nanjing, 210097, Jiangsu, China.
BMC Psychiatry. 2020 Feb 17;20(1):71. doi: 10.1186/s12888-020-02490-7.
Many studies have found that the hippocampus plays a very important role in major depressive disorder (MDD). The hippocampus can be divided into three subfields: the cornu ammonis (CA), dentate gyrus (DG) and subiculum. Each subfield of the hippocampus has a unique function and are differentially associated with the pathological mechanisms of MDD. However, no research exists to describe the resting state functional connectivity of each hippocampal subfield in MDD.
Fifty-five patients with MDD and 25 healthy controls (HCs) matched for gender, age and years of education were obtained. A seed-based method that imposed a template on the whole brain was used to assess the resting-state functional connectivity (rsFC) of each hippocampal subfield.
Patients with MDD demonstrated increased connectivity in the left premotor cortex (PMC) and reduced connectivity in the right insula with the CA seed region. Increased connectivity was reported in the left orbitofrontal cortex (OFC) and left ventrolateral prefrontal cortex (vlPFC) with the DG seed region. The subiculum seed region revealed increased connectivity with the left premotor cortex (PMC), the right middle frontal gyrus (MFG), the left ventrolateral prefrontal cortex (vlPFC) and reduced connectivity with the right insula. ROC curves confirmed that the differences between groups were statistically significant.
The results suggest that the CA, DG and subiculum have significant involvement with MDD. Specifically, the abnormal functional connectivity of the CA may be related to bias of coding and integration of information in patients with MDD. The abnormal functional connectivity of the DG may be related to the impairment of working memory in patients with MDD, and the abnormal functional connectivity of the subiculum may be related to cognitive impairment and negative emotions in patients with MDD.
许多研究发现，海马体在重度抑郁症（MDD）中起着非常重要的作用。海马体可以分为三个亚区：角回（CA）、齿状回（DG）和下托。海马体的每个亚区都有独特的功能，并且与 MDD 的病理机制有差异相关。然而，目前还没有研究描述 MDD 中海马体各亚区的静息状态功能连接。
获得 55 名 MDD 患者和 25 名性别、年龄和受教育年限相匹配的健康对照者（HCs）。采用一种基于模板的全脑种子方法来评估每个海马亚区的静息状态功能连接（rsFC）。
MDD 患者左前运动皮层（PMC）与 CA 种子区的连接增加，右岛叶与 CA 种子区的连接减少。DG 种子区与左眶额皮层（OFC）和左腹外侧前额叶皮层（vlPFC）的连接增加。下托种子区与左前运动皮层（PMC）、右额中回（MFG）、左腹外侧前额叶皮层（vlPFC）的连接增加，与右岛叶的连接减少。ROC 曲线证实组间差异具有统计学意义。
研究结果表明 CA、DG 和下托均与 MDD 有显著关联。具体而言，MDD 患者 CA 的异常功能连接可能与信息编码和整合偏倚有关。DG 的异常功能连接可能与 MDD 患者的工作记忆损伤有关，而下托的异常功能连接可能与 MDD 患者的认知障碍和负性情绪有关。
