Fastigio-olivary fibers in the cat as revealed by the autoradiographic tracing method.

The existence of fastigio-olivary fibers was shown in the cat by the autoradiographic tracing method. In the inferior olive contralateral to the fastigial nucleus injected with tritium amino acids, silver grains which suggested labeling of axon terminals were seen moderately in the dorsal cap and beta nucleus, and sparsely in the caudomedial portions of the medial accessory olive close to the beta nucleus.