P0和3个月龄大鼠海马CB1R的差异性表达

Differential expression of hippocampal CB1R between P0 and 3 month old rats

目的探讨P0大鼠和成年大鼠海马大麻素Ⅰ型受体(cannabinoid type 1 receptor,CB1R)表达特点。方法取P0和3个月龄大鼠各3只,灌注固定,取海马切片,行CB1R免疫组化检测,在显微镜下观察海马CB1R表达特征,行CB1R和胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)免疫双标荧光检测,在激光共聚焦显微镜下观察,明确CB1R表达细胞种类。结果CB1R免疫组化DAB显色,在P0期大鼠海马,CB1R呈片状分布,主要分布在锥体细胞层神经元胞体,而在3个月龄大鼠海马,CB1R呈点状分布,主要分布在锥体细胞层;CB1R和GFAP免疫双标显示,在P0期大鼠海马,CB1R主要分布在锥体细胞层神经元胞体,在CA1区各层呈现点状分布,星形胶质细胞无CB1R表达,在3个月龄大鼠海马,CB1R呈点状主要分布在锥体细胞层,星形胶质细胞无CB1R表达。结论刚出生SD大鼠和成年SD大鼠海马CB1R表达存在差异,从出生至成年,大鼠海马CB1R可能存在从神经元胞体向神经突触的迁移。

Objective To explore the expression characteristics of cannabinoid type 1 receptor(CB1 R)in hippocampus of P0 rats and adult rats.Methods Three P0 and 3 month old rats were perfused and fixed,and hippocampal slices were taken for CB1 R immunohistochemical detection.The expression characteristics of hippocampal CB1 R were observed under a microscope.CB1 R and glial fibrillary acidic protein(GFAP)immunological double-labeled fluorescence detection was performed.Under a laser confocal microscope,the types of cells expressing CB1 R were observed.Results CB1 R immunohistochemistry shows that CB1 R is mainly distributed in the neuron cell body of the pyramidal cell layer presenting patches in the P0 rat hippocampus,while in the 3-month-old rat hippocampus,CB1 R is mainly distributed in the pyramidal cell layer in dots.Double immunolabeling of CB1 R and GFAP showed that in the hippocampus of P0 rats,CB1 R was mainly distributed in the neuron cell body of the pyramidal cell layer,and dotted in each layer of the CA1 area,while astrocytes had no CB1 R expression.In the hippocampus of aged rats,CB1 R was mainly distributed in the pyramidal cell layer in a punctate manner,and there was no CB1 R expression in astrocytes.Conclusions There are differences in the expression of CB1 R in hippocampus between newborn SD rats and adult SD rats.From birth to adulthood,hippocampal CB1 R might migrate from neuronal cell bodies to synapses in rat.