Labeling of nerve cells in the dorsal motor nucleus of the vagus of rats by retrograde transport of Fluoro-Gold

Nerve cells in the dorsal motor nucleus of the vagus (dmnX) were identified by retrograde axonal transport after injections of a fluorescent tracer, Fluoro-Gold, into the anterior gastric wall. The intramural injection resulted in labeling of cells in the medial half of the left dmnX. These observations were contrasted with the diffuse (mediolateral and rostrocaudal) and bilateral distribution of labeled cells after Fluoro-Gold solution was dripped onto the stomach. In comparison with other neurotracers, the advantages of Fluoro-Gold are that (1) it can be visualized without the chemical reaction with chromogen, thereby allowing better reproducibility, and (2) it does not fade up to one year.