Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS 39216, USA.
J Psychiatr Res. 2013 Mar;47(3):299-306. doi: 10.1016/j.jpsychires.2012.10.020. Epub 2012 Nov 30.
Neuroimaging consistently reveals smaller hippocampal volume in recurrent or chronic major depressive disorder (MDD). The underlying cellular correlates of the smaller volume are not clearly known. Postmortem tissues from 17 pairs of depressed and control subjects were obtained at autopsy, and informant-based retrospective psychiatric assessment was performed. Formalin-fixed left temporal lobes were sectioned (40 μm), stained for Nissl substance, and every 60th section selected throughout the entire hippocampus. Total volume of the hippocampal formation was calculated, and total numbers of pyramidal neurons (in hippocampal fields CA1, CA2/3, hilus), dentate gyrus (DG) granule cells, and glial cells were estimated stereologically. While hippocampal volume in all MDD subjects was not significantly smaller versus control subjects, in recurrent/chronic MDD, total volume decreased with duration of depressive illness (r = -0.696, p < 0.026). There was no significant difference between MDD and controls in total number or density of pyramidal neurons/granule cells or glial cells in CA1, CA2/3, hilus, or DG. However, CA1 pyramidal neuron density increased with duration of illness in recurrent/chronic MDD (r = 0.840, p < 0.002). Granule cell (r = 0.971, p < 0.002) and glial cell numbers (r = 0.980, p < 0.001) increased with age in those taking antidepressant medication (n = 6). Increasing DG granule cell and glial cell numbers with age in antidepressant-treated subjects may reflect proliferative effects of antidepressant medications. Decreasing total volume and increasing CA1 pyramidal neuron density with duration of illness in recurrent/chronic MDD lends support to the neuropil hypothesis of MDD.
神经影像学研究一致显示，反复发作或慢性重度抑郁症（MDD）患者的海马体积较小。但是，目前尚不清楚较小体积的潜在细胞相关性。在尸检时从 17 对抑郁和对照受试者中获得了福尔马林固定的左颞叶组织，并进行了基于知情者的回顾性精神病学评估。对整个海马体进行了 Nissl 物质染色，并选择了每 60 个切片进行染色，以获得海马结构的总体积，并通过体视学方法估计海马 CA1、CA2/3、齿状回（DG）颗粒细胞和神经胶质细胞的总数。虽然所有 MDD 患者的海马体积与对照组相比没有明显减小，但在复发性/慢性 MDD 中，海马体积随着抑郁疾病持续时间的增加而减少（r = -0.696，p < 0.026）。在 MDD 和对照组之间，CA1、CA2/3、齿状回或 DG 中的总神经元/颗粒细胞或神经胶质细胞数量或密度没有显著差异。然而，在复发性/慢性 MDD 中，CA1 锥体神经元密度随着疾病持续时间的增加而增加（r = 0.840，p < 0.002）。在服用抗抑郁药的患者（n = 6）中，颗粒细胞（r = 0.971，p < 0.002）和神经胶质细胞数量（r = 0.980，p < 0.001）随年龄增长而增加。在服用抗抑郁药的患者中，DG 颗粒细胞和神经胶质细胞数量随年龄增长而增加，这可能反映了抗抑郁药的增殖作用。在复发性/慢性 MDD 中，随着疾病持续时间的增加，总体积减少和 CA1 锥体神经元密度增加，这支持了 MDD 的神经突假说。
