Effects of isoflurane anesthesia on proliferation and differentiation of neural stem cells in the dentate gyrus of neonatal rats

Abstract

Objective To investigate the effects of isoflurane anesthesia on proliferation and differentiation of neural stem cells (NSCs) in the dentate gyrus of neonatal rats.Methods Ten SD rats,aged 7 days,weighing 16-20 g,were randomly divided into 2 groups ( n =5 each):control group (group C) and isoflurane group (group 1) .The rats in group Ⅰ inhaled 2.5％ isoflurane for 3 min for induction and then anesthesia was maintained with 1.5 ％ isoflurane for 4 h,while the rats in group C only breathed the room air for 4 h.Bromodeoxyuridine (BrdU) 100 mg/kg was injected intraperitoneally right before the induction and after the end of administration to label NSCs and their progeny in the dentate gyrus.At 24 h after the 2nd administration of BrdU,double immunofluorescence for BrdU and NeuroD (a marker of neuroblasts and immature neurons) was used to assess NSC proliferation and neuronal differentiation.Results Compared with group C,the number of BrdU+ cells in group Ⅰ was significantly decreased,whereas the fraction of NeuroD+/BrdU+ differentiated cells was increased in the dentate gyrus( P ＜ 0.05 or 0.01 ).Conclusion Isoflurane anesthesia suppresses the proliferation of NSCs and induces neuronal differentiation of NSCs in the dentate gyrus of neonatal rats. Key words: Isoflurane; Dentate gyrus; Stem cells; Cell proliferation; Cell differentiation; Infant, newborn