Innervation of guinea-pig stellate ganglia by nitric oxide synthase, cocaine- and amphetamine-regulated transcript protein- and pituitary adenylate cyclase activating polypeptide-immunoreactive fibers.

Abstract The present study analyzed using immunohistochemical labeling the distribution and co-localization of nitric oxide synthase (NOS), cocaine- and amphetamine-regulated transcript peptide (CARTp) and pituitary adenylate cyclase activating polypeptide (PACAP) with choline acetyltransferase (ChAT)-immunoreactive fibers in the guinea-pig stellate ganglia. ChAT-immunoreactive fibers make pericellular baskets around virtually all stellate ganglia neurons. Pericellular baskets of NOS, CARTp and PACAP fibers were also present around numerous stellate ganglia neurons. Although all the NOS and PACAP fibers also exhibited ChAT immunoreactivity, only some of the CARTp fibers were ChAT-immunoreactive. No evidence of co-localization of NOS, PACAP and CARTp was obtained. These results indicate that NOS, PACAP and CARTp are present in distinct preganglionic axons innervating the guinea-pig stellate ganglia.