Effects of Melatonin on Differentiation of Rat Neural Stem Cell into Neuron-like Cells

To investigate the effect of melatonin on differentiation of rat neural stem cells in vitro. Neural stem cells, which depended on bFGF and EGF for surviving, were isolated from subventricular zone of neonate rat, cultured in vitro and used for experiment after identification by immunohistochemistry All cells were cultured in medium containing 10 mL/L fetal calf serum without growth factors, processed for immunohistochemistry staining one week after treatment with melatonin or luzindol, and the formation rate of Map2 positive cells among the experimental groups was compared. ① Neural stem cells generated neural spheres in vitro and expressed Nestin protein,and differentiated into GFAP ,S100 ,Map2 positive cells without growth factors ② Melatonin increased the formation rate of Map2 positive cells (23 45%,21 82%)(P0 01) ③ Luzindole, a competitive inhibitor of the binding of melatonin to the transmembrane receptors, blocked the effect of high concentration(100 μmol/L) of melatonin on the differentiation of neural stem cells into neuron like cells, but could not inhibit the action of melatonin in low concentration(10 nmol/L) [Conclusion] The results indicate that melatonin can accelerate differentiation of neural stem cells into neuron like cells, but there exists different effects between the low and high concentrations, which may refer to the different mechanisms of action on neural stem cells.