脑卒中后抑郁大鼠情感障碍相关脑区少突胶质细胞的表达变化

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

目的探讨脑卒中后抑郁（post—stroke depression，PSD）大鼠额叶、海马及杏仁核少突胶质细胞（Oligodendrocyte，OL）的表达变化，以了解其在PSD发病机制中的作用。方法将健康成年SD大鼠随机分为正常组、抑郁组、卒中组和PSD组，每组5只。卒中组采用线栓法建立局灶性脑缺血模型；抑郁组采用慢性不可预见的中等应激刺激（Chronic unpredictable mild stress，CUMS）结合孤养法建立大鼠慢性应激抑郁模型；PSD组采用线栓法建立局灶性脑缺血模型后，再加以CUMS及孤养法建立PSD大鼠模型。造模后对各组大鼠进行蔗糖水消耗试验（sucrose preferencetest，SPT）和旷场试验（open—field test，OFT）检测，并于造模后第29天应用免疫荧光染色法检测各组大鼠额叶、海马及杏仁核CNPase免疫阳性少突胶质细胞的表达变化。结果在CUMS后第29天，四组大鼠蔗糖溶液消耗量、旷场试验水平运动距离及垂直运动距离对比，抑郁组[（26．6±1．1）％；（63．6±2．3）cm；（26．4±1．1）cm]和PSD组[（23．8±0．8）％；（63．0±1．2）cm；（25．0±1．0）cm]较正常组[（31．2±1．9）％；（69．8±2．3）cm；（31．0±1．6）cm]和卒中组[（31．0±1．4）％；（70．2±2．4）cm；（30．8±1．1）cm]均明显降低，差异有统计学意义（P〈0．05）；四组大鼠CNPase免疫阳性少突胶质细胞在额叶、海马及杏仁核表达数目相比，卒中组[（16．60±1．82）个／视野；（14．60±1．82）个／视野；（15．00±2．12）个／视野]、抑郁组[（16．40±2．07）个／视野；（14．80±2．17）个／视野；（15．80＋2．28）个／视野]及PSD组[（12．40±1．52）个／视野；（11．20±1．48）个／视野；（10．80±1．92）个／视野]较正常组[（20．40±3．51）个／视野；（18．20±2．59）个／视野；（19．00±2．55）个／视野]均减少，差异有统计学意义（P〈0．05），其中PSD组较卒中组、抑郁组CNPase免疫阳性少突胶质细胞表达减少，差异有统计学意义（P〈0．05）。结论PSD大鼠在情感障碍相关脑区额叶、海马及杏仁核CNPase免疫阳性少突胶质细胞表达数目明显减少，少突胶质细胞在PSD发病过程中可能发挥了重要的作用。

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 oligodendroeytes 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 isehemie 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 isehemic 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 oligodendro- cytes 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.