The 2-deoxyglucose (2-DG) technique was used to investigate general and localized changes in metabolic activity within the brains of rats exposed to various drugs capable of producing physical dependence. Specifically, we studied the acute effects (one dose), chronic effects (long-term dosing), and the effects of withdrawal from ethanol, phenobarbital, and diazepam. We also investigated the effects of a given dose of diazepam on the ethanol withdrawal syndrome. Similarities were noted in the autoradiographs of animals withdrawing from the drugs studied. Among the similarities noted were a generalized increase in 2-DG uptake, 400-micrometer-wide columns of increased uptake in the frontal sensorimotor cortex, and ovoid areas of increased uptake in the cerebellum. These columns and ovoid areas of increased uptake were no longer visible in the autoradiographs of ethanol-withdrawing rats treated with diazepam before injection of the 2-DG. Differences were also noted in the uptake withdrawal from the three drugs studied. The most striking difference was a localized increase in 2-DG uptake in the dorsal portion of the lateral geniculate in animals withdrawing from phenobarbital and diazepam but not ethanol. Further statistical analysis is needed to identify other similarities and differences in the 2-DG uptake patterns of the withdrawals studied. The comparison of the acute doses of the drugs studied is more complicated. The acute studies of ethanol administration indicate that low doses (0.8 g/kg) increased, moderate doses (1.6 g/kg) decreased, and high doses (3.2 g/kg) showed a mixed response with respect to 2-DG uptake. Acute phenobarbital (100 mg/kg) decreased uptake, while no effect was observed on 2-DG uptake in animals treated acutely with diazepam (5 mg/kg). Further analysis is needed to identify additional differences in the acute animals as well as in the ethanol-withdrawing animals given diazepam.
