Cocaine self-administration alters brain NADH dehydrogenase mRNA levels.
Using differential display PCR, we identified a cDNA whose expression is altered in several brain regions in rats self-administering cocaine. The cDNA sequence corresponds to bases 13687-13723 of the rat NADH dehydrogenase subunit 6 gene. Northern analysis indicated a 26% decrease in nucleus accumbens, a 305% increase in the ventral midbrain and no changes in the caudate putamen mRNA levels; changes were also noted in the hypothalamus and cerebellum. This is the first demonstration of an effect of cocaine self-administration on mitochondrial gene expression and suggests that regional metabolic changes elicited by cocaine may be relevant to and involved in its reinforcing properties.