Collateral sprouting of somatosensory corticofugal axons into the cerebellar deafferented red nucleus

Light microscopic-autoradiographic findings indicate that, following chronic lesions of cerebellorubral projections in the adult cat, somatosensory corticofugal axons in the cerebral crus give rise to collateral sprouts which reinnervate the deafferented red nucleus. These data strongly suggest that these new axons reinnervate the deafferented soma and proximal dendrites of the rubral neurons. This reactive synaptogenesis may compete with terminal sprouting from motor corticorubral synapses already present on the distal dendrites of the rubral neurons.