Adrenergic chromaffin cells of the adrenal medulla are generated through recruitment of nerveassociated neural crest-derived cells termed Schwann cell precursors (SCPs). The present study evaluates the effect of serotonin precursor (5-HTP) on survival and proliferation of neural crest derived progenitors into chromaffin cells on E13.5 explants derived from C57BL/6 wild type mice. We also investigate whether serotonin (5-HT) enhances neurite outgrowth and proliferation in non-differentiated rat pheochromocytoma cells (PC12), which originate from chromaffin cells. Here we report that treatment with serotonin precursors resulted in a significant decrease of proliferating tyrosine hydroxylase positive (TH+) cells in the adrenal gland (AG). In addition, we demonstrated that serotonin enhances neurite outgrowth in non-differentiated cells. The preliminary data indicate the potential of serotonin to function as a new molecular target for neural crest-derived tumors as pheochromocytoma.