A characterization of nicotine-induced tolerance: evidence of pharmacological tolerance in the rat.

The present studies were conducted in order to confirm and extend previous findings that the mechanisms of tolerance to the behaviorally disruptive effects of nicotine in a operant model were primarily pharmacological. Both the traditional methodology employing the determination of dose response curves before and after chronic drug administration and a methodology which omits the generation of dose response curves were utilized in these investigations of nicotine-induced tolerance. Rats developed tolerance to both pre- and post-session administration of nicotine, suggesting that the mechanisms of tolerance to the disruptive effects of nicotine are primarily pharmacological. The mechanisms underlying these effects, however, remain to be evaluated.