A morphological study of ambiguus nucleus motoneurons innervating the laryngeal muscles in the rat and cat.

The location and axonal projections of laryngeal motoneurons (LMn) have been studied in rats and cats using horseradish peroxidase as a retrograde tracer. LMn are located in the caudal part of the ambiguus nucleus in both species. In the cat, LMn are organized in two groups with a specific orientation of their dendritic trees. LMn axonal projections are ipsilateral in cats and bilateral in rats.