Cerebellar nuclear afferents from the lateral reticular nucleus in the cat.

Cerebellar afferent fibers were anterogradely stained throughout their length after injections of horseradish peroxidase labeled wheat germ agglutinin in the lateral reticular nucleus in cats. Most fibers ascended through the ipsilateral restiform body, but a few fibers ran on the contralateral side. Some anterogradely stained fibers crossed the midline in cerebellum. Terminal fibers were present in the granular layer and in the cerebellar nuclei. Plexuses of nuclear terminal fibers were found in the ipsilateral interposed and dentate nuclei and were dense in the former. A smaller number of presumably terminal fibers were observed in the ipsilateral fastigial nucleus and in the contralateral cerebellar nuclei. The findings give further evidence for the lateral reticular nucleus being an important source of cerebellar nuclear afferents.