Stress reinstates nicotine seeking but not sucrose solution seeking in rats

Abstract

Rationale Intermittent footshock stress effectively reinstates extinguished heroin-, cocaine- and alcohol-taking behaviors, but not behaviors previously maintained by food reinforcers. Here we tested further the generality of the phenomenon of stress-induced reinstatement by determining the effect of footshock on reinstatement of operant responding previously maintained by nicotine or palatable sucrose solutions.Methods Groups of rats were trained to self-administer either nicotine (0.03 mg/kg per infusion, 14 days) or sucrose (10 or 30% w/v, 14-20 days). After extinction of the nicotine- or the sucrose-reinforced behaviors for 5-15 days, the rats were exposed to intermittent footshock stress (5 and 15 min, 0.8 mA) during tests for reinstatement.Results Footshock reliably reinstated nicotine seeking after extinction of the drug-reinforced behavior. In contrast, the same parameters of footshock stress did not consistently reinstate operant responding previously maintained by sucrose solutions.Conclusions These and previous data suggest that stressors may be more effective stimuli for reinstatement of behaviors previously maintained by drug reinforcers as compared with non-drug reinforcers.