Wang Zan, Yuan Yonggui, Bai Feng, Shu Hao, You Jiayong, Li Lingjiang, Zhang Zhijun
Neurology Department, Affiliated ZhongDa Hospital, Neuropsychiatric Institute and Medical School of Southeast University, Nanjing, 210009, China.
Neurosci Bull. 2015 Feb;31(1):13-21. doi: 10.1007/s12264-014-1489-1. Epub 2015 Jan 6.
The regional specificity of hippocampal abnormalities in late-life depression (LLD) has been demonstrated in previous studies. In this study, we sought to examine the functional connectivity (FC) patterns of hippocampal subregions in remitted late-onset depression (rLOD), a special subtype of LLD. Fourteen rLOD patients and 18 healthy controls underwent clinical and cognitive evaluations as well as resting-state functional magnetic resonance imaging scans at baseline and at ∼21 months of follow-up. Each hippocampus was divided into three parts, the cornu ammonis (CA), the dentate gyrus, and the subicular complex, and then six seed-based hippocampal subregional networks were established. Longitudinal changes of the six networks over time were directly compared between the rLOD and control groups. From baseline to follow-up, the rLOD group showed a greater decline in connectivity of the left CA to the bilateral posterior cingulate cortex/precuneus (PCC/PCUN), but showed increased connectivity of the right hippocampal subregional networks with the frontal cortex (bilateral medial prefrontal cortex/anterior cingulate cortex and supplementary motor area). Further correlative analyses revealed that the longitudinal changes in FC between the left CA and PCC/PCUN were positively correlated with longitudinal changes in the Symbol Digit Modalities Test (r = 0.624, P = 0.017) and the Digit Span Test (r = 0.545, P = 0.044) scores in the rLOD group. These results may provide insights into the neurobiological mechanism underlying the cognitive dysfunction in rLOD patients.
以往研究已证实老年期抑郁症（LLD）中海马异常的区域特异性。在本研究中，我们试图检验缓解期晚发性抑郁症（rLOD，LLD的一种特殊亚型）中海马亚区的功能连接（FC）模式。14例rLOD患者和18名健康对照者在基线期及随访约21个月时接受了临床和认知评估以及静息态功能磁共振成像扫描。每个海马被分为三个部分，即海马角（CA）、齿状回和下托复合体，然后建立了六个基于种子点的海马亚区网络。直接比较了rLOD组和对照组中六个网络随时间的纵向变化。从基线期到随访期，rLOD组显示左侧CA与双侧后扣带回皮质/楔前叶（PCC/PCUN）之间的连接性下降幅度更大，但右侧海马亚区网络与额叶皮质（双侧内侧前额叶皮质/前扣带回皮质和辅助运动区）的连接性增加。进一步的相关性分析显示，rLOD组中左侧CA与PCC/PCUN之间FC的纵向变化与符号数字模态测验（r = 0.624，P = 0.017）和数字广度测验（r = 0.545，P = 0.044）分数的纵向变化呈正相关。这些结果可能为rLOD患者认知功能障碍潜在的神经生物学机制提供见解。
