Peptide coincidence in rat superior cervical ganglion.

The immunofluorescent localization of substance P (SP), somatostatin and methionine enkephalin has been determined in the rat superior cervical ganglion of the sympathetic nervous system. Immunoreactivity was confined to the norepinephrine-containing post-ganglionic neurons and their processes. Nearly 20% of the postganglionic somata demonstrate dual coincidence in staining for SP-somatostatin, somatostatin-enkephalin, or SP-enkephalin. Almost 10% of the positively stained neurons show a coincident staining of all 3 peptide compounds within their somata. This suggests that multiple neurotransmitter chemicals may be employed by the postganglionic cells of the superior cervical ganglion.