Pituitary adenylate cyclase-activating polypeptide plays a key role in nitroglycerol-induced trigeminovascular activation in mice

► Chemical activation of the trigeminovascular system was made by NTG and PACAP-38. ► Light-aversion, meningeal vasodilatation and neural activation were assessed. ► These symptoms are significantly reduced in PACAP-deficient mice. ► I.p. PACAP evokes similar changes in wildtype, but not in PACAP-deficient mice. ► Pivotal roles of PACAP in trigeminovascular activation in mice have been revealed.