The expression of oligodendrocytes in the emotional disorder-related brain areas of the post-stroke depression model rats

Abstract

Objective To explore the expression of the CNPase positive oligodendrocytes in the frontal cortex, hippocampus and amygdala of the post-stroke depression (PSD) model rats, and to understand the role of oligodendrocytes in the pathogenesis of PSD. Methods Healthy adult SD rats were randomly divided into normal group, depression group, stroke group, and PSD group(n=5 in each group). In the stroke group, focal cerebral ischemic rat model was made with thread embolization method. In the depression group, the depression model rats were made by chronic unpredictable mild stress(CUMS) combined with separately breeding.In the PSD group, focal cerebral ischemic rat model was made with thread embolization method firstly, and then PSD rat model was established with comprehensive chronic unpredictable mild stress(CUMS) and separately breeding on this basis.After the procedure, rats were subjected to sucrose preference test(SPT) and open field test(OFT). Immunofluorescence staining was used to detect the expression of the CNPase positive oligodendrocytes in the frontal cortex, hippocampus and amygdala at day 29. Results On the 29th day after CUMS, comparing the sucrose solution consumption, horizontal movement distance of open field test and vertical movement distance of the each group, the depression((26.6±1.1)%, (63.6±2.3)cm, (26.4±1.1)cm) and the PSD groups((23.8±0.8)%, (63.0±1.2)cm, (25.0±1.0)cm) were significantly lower than normal((31.2±1.9)%, (69.8±2.3)cm, (31.0±1.6)cm)and the stroke groups((31.0±1.4)%, (70.2±2.4)cm, (30.8±1.1)cm)(P<0.05). Comparing the expression of the CNPase positive oligodendrocytes in the frontal cortex, hippocampus and amygdala of the each group, the number of the stroke((16.60±1.82), (14.60±1.82), (15.00±2.12)), depression((16.40±2.07), (14.80±2.17), (15.80±2.28)) and the PSD groups((12.40±1.52), (11.20±1.48), (10.80±1.92)) were significantly less than that in normal group((20.40±3.51), (18.20±2.59), (19.00±2.55)), and the number of expression CNPase positive oligodendrocytes in the PSD group was significantly less than that in stroke and depression groups(all P<0.05). Conclusion The number of the CNPase positive oligodendrocytes in PSD group in the emotional disorders related brain areas(the frontal lobe, hippocampus and amygdale) reduced obviously, and the oligodendrocytes may play an important role in the pathogenesis of PSD. Key words: Post-stroke depression; Oligodendrocytes; Frontal lobe; Hippocampus; Amygdala