Differential effects of acute administration of clozapine or haloperidol on local cerebral glucose utilization in the rat.
We employed the [14C]2-deoxyglucose method in order to map local brain metabolic activity of rats administered 1, 5, or 20 mg/kg of clozapine, or 0.5 mg/kg of haloperidol, as compared to saline. Clozapine produced a dose-dependent reduction of glucose utilization. At the dose of 1 mg/kg, the effects were limited to limbic areas. An additional number of structures were significantly affected following administration of 5 mg/kg (the whole hippocampal formation and septal area, and cortical limbic areas). The dose of 20 mg/kg markedly reduced glucose utilization in most of the areas examined. Haloperidol (0.5 mg/kg) reduced glucose utilization of the orbital cortex, hippocampal formation and septal area, globus pallidus, amygdala, ventral thalamus, and substantia nigra reticulata. The results show that acute administration of clozapine or haloperidol are associated with different distribution patterns of altered cerebral energy metabolism. Clozapine differently from haloperidol, reduces energy metabolism of the nucleus accumbens and other limbic areas. Haloperidol, but not clozapine (1 or 5 mg/kg), affects the substantia nigra reticulata.