NITRIC-OXIDE SYNTHASE-CONTAINING NEURONS IN RAT PARASYMPATHETIC, SYMPATHETIC AND SENSORY GANGLIA - A COMPARATIVE-STUDY

In rats, the distribution of nerve structures staining for NADPH-diaph orase, and showing immunoreactivities for nitric oxide synthase (NOS), tyrosine hydroxylase and various neuropeptides was studied in sensory ganglia (dorsal root, nodose and trigeminal ganglia), in sympathetic ganglia (superior cervical, stellate, coeliac-superior and inferior me senteric ganglia), parasympathetic ganglia (sphenopalatine, submandibu lar, sublingual and otic ganglia), and in the mixed parasympathetic/sy mpathetic ganglia (major pelvic ganglia). The coincidence of neuronal cell bodies with strong NOS-immunoreactivity and strong NADPH diaphora se reactivity was almost total. The relative proportions of NOS-immuno reactive nerve cell bodies were largest in parasympathetic ganglia and major pelvic ganglia followed by sensory ganglia. In sympathetic gang lia no NOS-immunoreactive neuronal cell bodies could be detected. In p arasympathetic and major pelvic ganglia, there was a very significant neuronal co-localization of immunoreactivities for NOS and vasoactive intestinal polypeptide (VIP). This was almost total in major pelvic ga nglia, in which NOS-/VIP-immunoreactive nerve cell bodies were separat e from sympathetic (tyrosine hydroxylase-/neuropep tide Y-immunoreacti ve), suggesting that NOS-/VIP-immune-reactive neurons might also be pa rasympathetic.