Using the monkey as a model for human hemispherectomy, the effects of early
removal of a whole cerebral hemisphere on the cytoarchitecture and cytochr
ome oxidase histochemistry of the superior colliculus (SC) were evaluated.
Results show that the SC ipsilateral to the cortical lesion suffers a 29.9%
average volume reduction and a 32.7% total loss of neurons compared to the
contralateral SC. Neuronal densities and metabolic activity are similar in
normal and hemispherectomized monkeys. Furthermore, the ipsi- and contrale
sional SC receive retinal inputs as revealed with intraocular injections of
tritiated proline. These data suggest that the superior colliculus retains
functional capabilities following hemispherectomy in monkey. (C) 2001 Else
vier Science B.V. All rights reserved.