Innervation and effects of dilatory neuropeptides on cerebral vessels. New aspects

The cerebral circulation is supplied with two vasodilator systems: the parasympathetic system storing vasoactive intestinal peptide, peptide histidine isoleucine, acetylcholine and in a subpopulation of nerves neuropeptide Y, and the sensory system, mainly originating in the trigeminal ganglion, storing substance P, neurokinin A and calcitonin gene-related peptide (CGRP). Recent knowledge of the innervation and effects of the dilator neuropeptides in the cerebral circulation is reviewed. Their role in the pathophysiology of subarachnoid hemorrhage and migraine has now received attention, with documentation of a clear linkage with the release of CGRP. In subarachnoid hemorrhage, other perivascular peptides are, to a lesser extent, involved.