Basal Gangha Glucose Uthzation after Precentral Ablation in the Monkey

In the macaque monkey, unilateral ablation of areas 4 and 6 of Brodmann results initially i n a significant decrease of glucose metabolic activity in the ipsilateral caudate nucleus, putamen, globus pallidus, substantia nigra, and subthalamic nucleus. The contralateral hemisphere shows nonsignificant bu t consistently decreased activity in the caudate nucleus, putamen, and globus pallidus. Cerebral blood flow is decreased in the same pat tern as the glucose metabolic activity. The change in glucose metabolic activity results from loss of neurons known to project directly from the cerebral cortex to the basal ganglia and also f rom indirect effects (diaschisis) i n basal ganglia structures that do not receive connections from the cerebral cortex.