慢性不可预知性应激对大鼠海马CA1区星形胶质细胞的影响

The effects of chronic unpredictable stress on astrocytes in the hippocampal CA1 of rats

目的:研究慢性不可预知性应激(CUS)模型大鼠海马CA1区内星形胶质细胞的改变,探讨星形胶质细胞在抑郁症中的作用。方法:选用雄性SD大鼠,随机分为空白对照组和抑郁模型组,利用CUS刺激制备大鼠抑郁模型,利用糖水偏好实验(SPT)筛选出成模大鼠。随后每组随机抽取5只大鼠,利用免疫组织化学方法结合现代体视学对大鼠海马CA1区内胶质纤维酸性蛋白(GFAP)阳性星形胶质细胞的数量进行精确的三维定量研究,利用免疫荧光染色方法检测大鼠海马CA1区内溴脱氧核苷尿嘧啶(BrdU)和GFAP的表达。结果:CUS干预5周后,抑郁模型组大鼠的体质量及糖水偏好百分比均显著低于空白对照组(P<0.05);抑郁模型组大鼠海马CA1区内GFAP阳性细胞的数量、BrdU阳性细胞及BrdU/GFAP双标细胞的密度均显著低于空白对照组(P<0.05)。结论:抑郁症CUS模型大鼠海马CA1区内星形胶质细胞的总数量及其新生细胞减少,提示了抑郁症海马CA1区内星形胶质细胞的数量及其新生细胞的改变可能是抑郁症重要的病理改变之一。

Objective:In order to study the effect of astrocytes in depression,we used the chronic unpredictable stress(CUS)depression rat model to investigate the changes of astrocytes in hippocampus CA1 area.Methods:Adult male Sprague-Dawley(SD)rats were randomly divided into the control group and the CUS group,and the CUS group was subjected to chronic stress for 5 weeks.The sucrose preference test(SPT)was used to assess anhedonia of rats.Then,immunohistochemistry and modern stereological methods were used to precisely quantify the total number of glial fibrillary acidic protein(GFAP)positive astrocytes in the CA1 area,and immunouorescence staining method was used to detect the expression of bromodeoxyuridine(BrdU)and GFAP cells in the CA1 area.Results:Five weeks after CUS,the sucrose preference and body weight of rats in the CUS group were found significantly lower than those in the control group(P<0.05).In addition,CUS intervention significantly reduced the total number of GFAP+cells and the density of BrdU+cells,and BrdU+/GFAP+cells in the CA1 area of hippocampus(P<0.05).Conclusions:The number of astrocytes and newborn astrocytes were decreased in the CA1 area in depression rat model.Thesendings suggested that the number of astrocytes and its newborn in the CA1 area might play a vital role in the pathogenesis of depression.