The article briefly describe the innervation of the human cerebral circulation by nerve fibers containing neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene-related peptide (CGRP). The neuropeptides in human cerebral arteries were characterized by radioimmunoassay in combination with HPLC. These neuropeptides mediate contraction (NPY) and dilation (VIP, SP, CGRP). In conjunction with spontaneous attacks of migraine or cluster headache, release of CGRP is seen. With the associated symptoms of nasal congestion and rhinorrhea, VIP is released. Successful treatment may abort the peptide release in parallel with disappearance of headache.