Demonstration of a sparse direct projection from the interstitial nucleus of Cajal to the cerebellum in the cat.

In the cat the possible contribution of cerebellar afferents from the accessory oculomotor nuclei was investigated by means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex. A sparse bilateral projection from the interstitial nucleus of Cajal was demonstrated. The fibres reach cerebellar cortical as well as nuclear regions. No retrogradely labelled cells were found in the nucleus of Darkschewitsch and the nucleus of the posterior commissure.