A serotoninergic system in the nodose ganglia of the cat: radioautographic studies

After the in vitro incubation of the cat nodose ganglia with 3H-5-HT, the radioautographic detection of the tracer at the light microscope level shows an intense labeling over some several hundred cell bodies. By ultrastructural studies, it has been possible to detect unmyelinated fibers intensely labeled and to characterize as neurons the labeled cell bodies. These data argue for the presence of 5-HT in some peripheral vagal afferents, obviously involved in vegetative regulatory mechanisms.