Effects of Dopamine Antagonists and Apomorphine on Regional Energy Metabolism in Rat CNS

Abstract

Alterations in 2-[14C]deoxyglucose uptake were studied in 154 brain regions from animals acutely challenged with a dopamine (DA) agonist or antagonist. Doses of apomorphine inducing locomotion and stereotypic behavior produced increased uptake in the subthalamic nucleus, the substantia nigra reticulata, and the ventroanterior and ventrolateral nuclei of the thalamus while decreased uptake was observed in the lateral habenula and several midline thalamic nuclei. The six centrally active DA antagonists studied produced uniform increases in uptake in the lateral habenula and the anterior regions of both the n. accumbens and striatum whereas decreased uptake was observed in the mesencephalic reticular formation and the reticular nucleus of the thalamus. Low doses of apomorphine that produced behavioral hypoactivity resulted in a pattern of metabolic alterations that resembled those associated with DA antagonists more closely than metabolic alterations seen with DA agonists. These results suggest that unique alterations in neuronal activity in several brain regions, including the traditional dopaminergic projection areas, are associated with the expression of specific DA-mediated behaviors.