Vagal motor neurons innervating the stomach are site-specifically organized in the dorsal motor nucleus of the vagus nerve in rats.

The aim of the present study was to examine the neuroanatomical relationship between the brainstem and the stomach. For this purpose, by means of a horseradish peroxidase retrograde method, we identified the distribution of individual parasympathetic preganglionic neurons projecting to three specific gastric regions that have structural and functional differences in the rat stomach. Preganglionic neurons innervating the ventral forestomach were mainly distributed in the lateral part of the left dorsal motor nucleus of the vagus nerve, while those innervating both ventral corpus and antrum were chiefly located in the medial part of the left dorsal motor nucleus. On the other hand, preganglionic neurons projecting to the dorsal forestomach and the dorsal corpus and antrum were predominantly observed in the lateral and the medial part of the right dorsal motor nucleus, respectively. These results suggest that parasympathetic preganglionic neurons innervating the stomach are site-specifically organized in the dorsal motor nuclei.