Chronic methamphetamine abuse in human subjects is associated with neuronal toxicity, expressed behaviorally as cognitive deficits. Studies in rats were initiated to establish a model in which the time course to toxicity, reversibility of effects and potential effects of treatment modalities could be tested. Rats were subjected to a chronic treatment regimen that was designed to mimic the manner in which human methamphetamine abusers self-administer the drug. The effects of brain function were assessed using the 2-deoxy-D-[1-[C-14]]glucose (DG) method, which provides quantitative maps of regional cerebral metabolic rates for glucose (rCMRglc), an index of brain function. Compared to effects in control animals, chronic methamphetamine produced lower rCMRglc in 14 out of 34 regions assayed and in whole brain. The most robust effects occurred in the retrosplenial cortex, head of the caudate putamen, ventroposterior thalamic n. and core of the nucleus accumbens. Lower basal brain metabolism in rats receiving chronic methamphetamine may reflect the toxic effects of chronic use of this drug. The wide distribution of the metabolic effects of methamphetamine in the rat brain suggests that human abusers of this drug have extensive cerebral deficits that underlie their cognitive and emotional symptoms.
