The origin of vasoactive intestinal polypeptide (VIP) nerves in the feline nasal mucosa

The feline nasal mucosa is richly supplied with vasoactive intestinal polypeptide (VIP) immunoreactive nerve fibres. The nerves occur in the subepithelial connective tissue, around small blood vessels and around the acini of seromucous glands. The ptergopalatine ganglion contains numerous VIP immunoreactive nerve cell bodies among non-reactive ones. Extirpation of the ganglion results in an almost complete disappearance of VIP-containing nerves in the nasal mucosa, while sectioning of the preganglionic nerve (Vidian nerve) does not affect the number of nasal VIP nerves. Hence the bulk of VIP nerve fibers in the nasal mucosa derive from cell bodies located in the pterygopalatine ganglion.