Objective    To explore the effects of ecdysterone (EDS) on proliferation and differentiation of rat hippocampal neural stem cells (NSCs) in vitro.     Methods    NSCs of SD rat hippocampus were isolated and cultured in serum-free medium containing bFGF and EGF

then different doses of EDS were used to treat the NSCs. Clone counting and MTT assays were performed for the proliferation of NSCs; Immunofluorescence and flow cytometry were carried out for the cell differentiation.     Results    High doses of EDS (400 and 800 mg/L) treatment markedly inhibited the proliferation of rat hippocampal NSCs

while the low doses of EDS (50

100 and 200 ng/L) exhibited no effects on the NSCs proliferation. Treatment of NSCs with 200 mg/L EDS markedly increased the neurogenesis of NSCs in differential medium

while NSCs of other doses did not.     Conclusion    EDS regulates the proliferation and differentiation of NSCs in vitro

whereas only 200 mg/L EDS can increase the neurogenesis of rat hippocampal NSCs.