Dose-dependent effects of chronic amphetamine administration in local cerebral glucose utilization in rat.

The daily dose of amphetamine pretreatment may affect the development of behavioral-sensitized patterns in rodents and amphetamine psychosis in humans. This experiment investigated the regional cerebral metabolic changes in rats after pretreatment with different doses of amphetamine by the 2-[14C]deoxyglucose method. Rates of local cerebral glucose utilization were examined in 37 regions of the rat brain. The result showed generally maximal metabolic augmentation in the 5.0 mg/kg group instead of in the 1.0 or the 10.0 mg/kg groups. Behavioral testing using motor activity cages in rats with the same regimen found no difference among groups. The findings demonstrate that there might be a window effect by daily amphetamine dose on the development of drug dependence and amphetamine psychosis. It was suggested that the 2(-)[14C]deoxyglucose method could be used for further study of animal models of amphetamine psychosis.