Nicotine attenuates relapse to methamphetamine-seeking behavior (craving) in rats

This study clarifies the modulating action of the nicotinic cholinergic system on reinstatement of methamphetamine (MAP)-seeking behavior (craving) using an intravenous, self-administration paradigm in rats. After self-administration of MAP for 10 days, replacing MAP with saline solution (MAP withdrawal) gradually decreased lever-pressing responses. On the sixth day of MAP withdrawal, MAP (1.0 mg/kg, i.p.)-priming injection significantly increased lever-pressing responses (reinstatement of MAP-seeking behavior). This MAP-seeking behavior was attenuated by repeated nicotine administration for 5 days during MAP withdrawal, and this attenuating effect was antagonized by the nicotinic antagonist mecamylamine. These results suggest that the appearance of MAP-seeking behavior may be due to inactivation of the nicotinic cholinergic neuron. Furthermore, it is suggested that nicotinic activating agents may be useful in preventing relapse to drug abuse.