Differentiation of neural stem cells into astrocytes by low concentration of pituitary adenylate cyclase-activating polypeptide (PACAP)

Recently it has been reported that pituitary adenylate cyclase-activating polypeptide (PACAP) possesses diverse physiological functions in central nervous system. In this study, the effect of physiological concentrations of PACAP on the differentiation of neural stem cells is described. When neural stem cells were exposed to 0.2 nM PACAP, total number of the cells decreased during the 8 days-culture. However, number of MAP2-immunopositive cells decreased while GFAP-immunopositive cells increased depending on the concentration of PACAP (0.2-2 nM). Neural stem cells were differentiated into astrocytes even at a concentration below 2 nM. These results indicate that PACAP at a low concentration prefers induction of differentiation into astrocytes rather than proliferation in neural stem cells.