Afferent projections to the caudal part of the dorsal nucleus of the raphe in cats.

Horseradish peroxidase (HRP) was iontophoresed into the caudal part of the dorsal nucleus of the raphe (DNR) in cats. Labeled neurons with HRP were recognized in the medial and the superior vestibular nucleus. Electrical stimulation of the medial or the superior vestibular nucleus elicited orthodromic evoked potentials and unitary responses in the caudal part of the DNR. These projections may be involved in eye movement control. In addition, labeled neurons were located in the magnocellular division of the alaminar spinal trigeminal nucleus. This projection may be a part of the pathway conveying somatosensory inputs from the face to the cerebellar flocculus.