Sex and diet-dependent gene alterations in human and rat brains with a history of nicotine exposure.

These results suggest that a history of long-term nicotine exposure in humans alters the expression of sphingolipid metabolism-related (, , and ) and neuronal () marker genes similarly as compared to rats. Sex- and diet-dependent differences appear in nicotine-exposed rats, critical in regulating sphingolipid metabolism and nicotinic acetylcholine receptors. This research enhances the construct validity of rat models of nicotine usage by showing a similar pattern of changes in gene expression in human subjects with a smoking history.