Quantitative and qualitative characteristics of dentate and fastigial afferents identified by electron microscopic autoradiography in the cat thalamus.

Dentato- and fastigiothalamic afferents were identified in the VM and medial VA and VL using electron microscopic (EM)-autoradiography. Synaptic vesicles in labeled dentate and fastigial boutons differed significantly in both their size and shape, which allows these two types of terminals to be distinguished in the normal neuropil. Differences in the mode of termination of cerebellar afferents upon the neurons in the thalamic nuclei studied are also discussed.