Differential effects of nicotine in inbred and selectively bred rodents.

The present review summarizes information about strain differences in the effects of nicotine. Earlier studies reported that rats selectively bred for behavioral differences (Maudsley, Roman) were differentially sensitive to the activating/depressing effects of nicotine, but few mechanistic studies were carried out. On the other hand, Collins and colleagues have conducted a comprehensive series of studies on inbred and crossbred mice, concluding that functional differences in nicotinic sensitivity can be but are not necessarily associated with differences in nicotine receptors. There is also consistent animal literature suggesting an association between alcohol and nicotine sensitivities. Finally, differences to nicotine have only recently been discovered in the Flinders Line rats, selectively bred for differences in sensitivity to an anticholinesterase agent. Some of the differences in nicotine sensitivity may depend upon underlying differences in muscarinic sensitivity, in nicotinic receptors, and/or dopaminergic mechanisms.