The PACAP Receptor: A Novel Target for Migraine Treatment

The origin of migraine pain has not yet been clarified, but accumulating data point to neuropeptides present in the perivascular space of cranial vessels as important mediators of nociceptive input during migraine attacks. Pituitary adenylate cyclase-activating polypeptide (PACAP) is present in sensory trigeminal neurons and may modulate nociception at different levels of the nervous system. Human experimental studies have shown that PACAP-38 infusion induces marked dilatation of extracerebral vessels and delayed migraine-like attacks in migraine patients. PACAP selectively activates the PAC1 receptor, which suggests a possible signaling pathway implicated in migraine pain. This review summarizes the current evidence supporting the involvement of PACAP in migraine pathophysiology and the PAC1 receptor as a possible novel target for migraine treatment.