[Afferent projections to the uvula in the cat. I. Climbing fiber projections]

The inferior olive afferents to the cerebellar uvula were studied by means of retrograde axonal transport of horseradish peroxidase (HRP) in the cat. Following large and small injections of HRP into the uvula, the distributions of labeled cells in the inferior olive were investigated. As to the climbing fiber projection, it is revealed that there are six longitudinal parasagittal zone extending throughout the dorsal and ventral uvula. That is, the caudal aspect of the nucleus beta projects to a most medially oriented zone (caudal beta zone), the rostral aspect of the nucleus beta projects to a zone (rostral beta zone) oriented lateral to the caudal beta zone, the caudal aspect of the medial accessory olive (MAO) projects to a zone oriented lateral to the rostral beta zone, the dorsomedial cell column projects to a zone (dorsomedial cell column zone) oriented in the intermediate part of the uvula, the ventral lamella of the principal olive (vlPO) projects to a more lateral zone (vlPO zone), and the rostral aspect of the MAO projects to the most lateral zone (rostral MAO zone).