Origins of nerve terminals containing nitric oxide synthase in the guinea-pig coeliac ganglion

Abstract

Nitric oxide synthase was localised immunohistochemically and by NADPH diaphorase activity in two groups of nerve terminals and in rare cell bodies in the guinea-pig coeliac ganglion. Strongly reactive varicose terminals surrounded a subgroup of principal ganglion cells, most of which were in the medial lobes of the ganglion and most of which were somatostatin immunoreactive. A second set of varicose terminals, which were less intensely reactive, were found throughout the ganglia. Nitric oxide synthase containing nerve cell bodies in the intermediolateral cell columns of the spinal cord were labelled by dye retrogradely transported from the coeliac ganglion. Lesion of nerve connections between abdominal viscera and the coeliac ganglion caused a loss of the strongly reactive fibres, while the widely distributed, less intensely reactive fibres persisted. It is concluded that nitric oxide synthase terminals in the coeliac ganglion come from two sources, sympathetic preganglionic neurons and intestinofugal neurons.