Effects of sevoflurane on hippocampal neurogenesis in dentate gyrus of mice of different ages

Objective To evaluate the effects of sevoflurane on hippocampal neurogenesis in dentate gyrus (DG) of mice of different ages. Methods Ninety-six SPF healthy male C57BL/6 mice, aged 2 weeks, 6 weeks, 9 months and 20 months (24 mice for each age, 12 mice for each group), were divided into 2 groups (n=48 each) using a random number table method: control group (group C) and sevoflurane group (group S). Group S inhaled 3.0% sevoflurane for 2 h once a day for 3 consecutive days, while group C inhaled the mixture of air and O2.Six mice of each age were selected, and 5′-bromo-2′-deoxyuridine (BrdU) 50 mg/kg was intraperitoneally injected immediately before and after inhalation once a day for 3 consecutive days in two groups.Mice were sacrificed at 24 h after the last inhalation (T1), brains were removed and hippocampi isolated for determination of the number of nestin and doublecortin (DCX) positive cells in DG by immunohistochemistry.Mice were sacrificed at 4 weeks after the last inhalation (T2), brains were removed and hippocampi isolated for determination of the number of neuronal nuclei antigen (NeuN)/BrdU and glial fibrillary acid protein (GFAP)/BrdU positive cells by immunofluorescence. Results Compared with group C, the number of nestin and DCX positive cells was significantly reduced at T1, and the number of NeuN/BrdU and GFAP/BrdU positive cells was reduced at T2 in mice of 2 weeks and 20 months old (P 0.05). Conclusion Three percent sevoflurane can inhibit hippocampal neurogenesis in DG of immature and old mice and exerts no influence on hippocampal neurogenesis in DG of juvenile and adult mice. Key words: Anesthetic, inhalation; Age; Neurogenesis; Hippocampus