Vasoactive intestinal polypeptide immunoreactive and cholinergic nerves in the whole mount preparation of the major cerebral arteries of the rat.

An immunofluorescence histochemical study of vasoactive intestinal polypeptide (VIP) was made in the major rat cerebral arteries of the whole mount preparation. A comparison was made between the distribution of VIP-immunoreactive and cholinergic nerves. An abundant number of VIP-containing nerves were observed in the internal carotid, anterior cerebral, middle cerebral and basilar artery. VIP and cholinergic nerves were unaffected by bilateral superior cervical ganglionectomy. The density and distribution of VIP-immunoreactive fibers was essentially the same as that of the cholinergic fibers of the rat cerebral vasculature. It is suggested that, as was previously demonstrated in other peripheral organs, VIP coexists within cholinergic neurons of the rat cerebral arteries.