Glucocorticoids dexamethasone and hydrocortisone inhibit proliferation and accelerate maturation of chicken cerebellar granule neurons

► We have tested GC effects on granule neurons in the chicken embryo cerebellum and in cerebellar neuronal cell culture. ► Both GCs, dexamethasone and hydrocortisone, reduce neuronal proliferation in the chicken cerebellum in vivo and in vitro. ► Dexamethasone and hydrocortisone increase neuronal differentiation in the chicken cerebellum in vivo and in vitro. ► The cytostatic agent cytosine arabinoside gives a similar effect to that of GCs in neuronal culture. ► Together these results indicate a connection between inhibition of the cell cycle and increased differentiation.