An autoradiographic study on the terminal distribution of cerebellothalamic fibers in the cat.

Distribution of cerebellothalamic fibers was studied in the cat by the anterograde tracing method. The vast majority of cerebellothalamic fibers were distributed contralaterally. The fastigial fibers arose mostly from the caudal half of the nucleus. These ended moderately in the VM and the most ventromedial regions of the VA-VL complex, and sparsely in the ventral portions of the CL, Pc and NCM; a few also ended in the CM and ZI. The dentate fibers ended moderately in the median and rostrodorsal VA-VL regions, and sparsely in the VM, CL, NCM, CM, LP and MD. The existence of the dentatopulvinar fibers was also confirmed. The posterior interpositus fibers ended heavily in the central VA-VL regions, moderately in the subparafascicular nucleus and ZI, and sparsely in the CM and the ventral lateral geniculate nucleus. The anterior interpositus fibers ended mainly in the ventrolateral VA-VL regions, and additionally in the CL and CM. The ipsilateral cerebellothalamic fibers arose mainly from the fastigial nucleus, and additionally from the dentate nucleus; those arising from the interpositus nuclei were very sparse.