PCPA致大鼠NG2细胞的变化,NG2与GABA的共存关系及酸枣仁汤的干预作用研究

Changes in rat NG2 cells induced by para-chlorophenylalanine,coexisting relationship between NG2 cells andγ-aminobutyric acid,and therapeutic effect of Suanzaoren decoction

目的:探讨大鼠脑内五羟色胺(5-HT)含量下降后皮质部分NG2细胞的变化,NG2细胞与星形胶质细胞(Ast)、γ-氨基丁酸(GABA)的共存关系及酸枣仁汤的干预作用。方法:根据随机数字表法将雄性SD大鼠分为7 d正常组、7 d对照组、7 d对氯苯丙氨酸(PCPA)组、15 d正常组、15 d对照组、15 d PCPA组、酸枣仁汤(SZRD)组、PCPA+SZRD组,各组大鼠给予相应处理。取大脑皮质前额叶,采取免疫荧光双染法测定大鼠皮质NG2细胞、胶质纤维酸性蛋白(GFAP)、GABA的表达量及NG2/GFAP、NG2/GABA共存定位情况。结果:与7 d对照组比较,7 d PCPA组大鼠皮质NG2细胞、GFAP蛋白表达量增加(P<0.01),GABA蛋白表达量下降(P<0.05);与15 d PCPA组比较,PCPA+SZRD组大鼠皮质NG2细胞、GFAP蛋白表达量下降(P<0.01),GABA表达量上升(P<0.05);NG2细胞与GABA在同一区域表达较多,而与GFAP在同一区域表达较少。结论:5-HT系统的失调能激活皮质NG2细胞、Ast,抑制GABA的表达,NG2细胞可能与Ast、GABA共同影响大脑皮层兴奋性来调节睡眠,酸枣仁汤可能通过5-HT系统调控NG2细胞、Ast、GABA来参与皮层活动的神经调节。

Objective:To investigate the changes in NG2 cells in the cortex after the reduction in5-hydroxytryptamine in rat brain,the coexisting relationship between NG2 cells and astrocytes(Ast)/γ-aminobutyric acid(GABA),and the therapeutic effect of Suanzaoren decoction.Methods:Male Sprague-Dawley rats were divided into 7-day normal group,7-day control group,7-day para-chlorophenylalanine(PCPA)group,15-day normal group,15-day control group,15-day PCPA group,Suanzaoren decoction(SZRD)group,and PCPA+SZRD group using a random number table,and each group was given corresponding treatment.The prefrontal lobe was collected,and double immunofluorescence staining was used to measure NG2 cells and the expression of glial fibrillary acidic protein(GFAP)and GABA in rat cortex,as well as the coexistence and localization of NG2/GFAP and NG2/GABA.Results:Compared with the 7-day control group,the 7-day PCPA group had significant increases in NG2 cells and the protein expression of GFAP(P<0.01)and a significant reduction in the protein expression of GABA(P<0.05).Compared with the 15-day PCPA group,the PCPA+SZRD group had significant reductions in NG2 cells and the protein expression of GFAP(P<0.01)and a significant increase in the protein expression of GABA(P<0.05).Coexistence of both NG2 cells and GABA was observed in the same region,while coexistence of NG2 cells and GFAP was not commonly seen in the same region.Conclusion:Dysregulation of the 5-HT system can activate NG2 cells and Ast in the cortex and inhibit the expression of GABA,and NG2 cells may affect the excitability of the cerebral cortex together with Ast and GABA to regulate sleep.Suanzaoren decoction may participate in the neuroregulation of cortical activity by regulating NG2 cells,Ast,and GABA via the 5-HT system.