Projections of bombesin-like immunoreactive fibers from the rat stomach to the celiac ganglion revealed by a double-labeling technique.

Gastrofugal bombesin (BOM)-like immunoreactive (BOMI) structures in the rat were studied by immunocytochemistry combined with retrograde labeling. Transection of the mesenteric nerve peripheral to the celiac ganglion resulted in the complete disappearance of BOMI nerve terminals, whereas transection of the splanchnic nerves did not alter the immunoreactivity. Injection of biotinylated wheat germ agglutinin into the celiac ganglion labeled several neurons in the myenteric ganglion of the stomach. Simultaneous staining with antiserum against BOM showed that some of them are BOMI-positive. These findings demonstrate that BOMI neurons in the myenteric ganglion of the rat stomach project to the celiac ganglion.