Effects of Propofol on the Proliferation and Differentiation of NG2 Cells in the Hippocampus of Aged Rats

Introduction: Anaesthetics can lead to cognitive impairment and partly recover. Whether this process is related to NG2 cells has not been reported. The present study aims to investigate the effects of propofol on the proliferation and differentiation of NG2 cells in the hippocampus of aged rats. Material and Methods: A total of 80 healthy SD rats were used for the investigation. These rats were randomly divided into two groups: control group (group C, n = 20) and anesthetic group (group A, n = 60). Rats in group A were continuously anesthetized by intravenous infusion of propofol for three hours, and underwent shuttle box test at seven days (A7), 14 days (A14) and three months (A3m) after anesthesia. Then, these rats were further divided into two groups: POCD group (three sub-groups: P7 group, P14 group and P3m group) and non-POCD group (three sub-groups: groups NP7, NP14 and NP3m). Results: Compared with group C, NG2 and PCNA cells in group A were upregulated at seven and 14 days after anesthesia. Compared with group C, MAP2 expression was downregulated, and OX42 and GFAP expression was upregulated in the POCD group, while MAP2 expression in the non-POCD group was upregulated. Compared with the non-POCD group, in the NG2 positive cells, MAP2 expression was downregulated, while OX42 and GFAP expression was upregulated in the POCD group, MAP2 expression was urelugated gradually during the 14th days after anesthesia (P < 0.05 or P < 0.01). Conclusions: Propofol induces neuronal apoptosis and the proliferation of NG2 cells. The direction of NG2 cell differentiation may be correlated to the recovery of cognitive dysfunction.