Morphology and distribution of the preganglionic parasympathetic neurons of the facial, glossopharyngeal and vagus nerves in the Japanese toad: a cobaltic lysine study.

We labelled the preganglionic parasympathetic neurons of the facial, glossopharyngeal and vagus nerves of the Japanese toad by applying the cobaltic lysine to the cut end of the respective nerve, and examined their morphology and distribution. These neurons form an almost continuous cell column consisting of small neurons with less elaborate dendrites, and occupy a more dorsal position than the motoneurons of the corresponding nerves. The results suggest the presence of the amphibian homologues of the salivatory nucleus and the dorsal motor nucleus of the vagus.