Saccular afferent fibers to the cochlear nucleus in the guinea pig.

After tracing the vestibular nerve of the guinea pig with horseradish peroxidase (HRP), a conspicuous fiber bundle was found that passed to the ipsilateral cochlear nucleus. HRP-labeled fibers were seen to leave the descending vestibular nucleus at a level caudal to subgroup "y" in a lateral direction. Travelling close to the restiform body, the axons terminated at cells lying between the dorsal and posteroventral cochlear nucleus. These cells could be distinguished cytoarchitecturally from surrounding cells of the cochlear nuclei. Several electrophysiological investigations have assumed that there is a direct connection between the vestibular and the cochlear system. Compared to these, the fibers under consideration might be the morphological basis for such a "vestibulo-cochlear anastomosis."