Effect of schedule of reinforcement on cue-elicited reinstatement of cocaine-seeking behavior

Behav Pharmacol. 2008 Mar;19(2):129-36. doi: 10.1097/FBP.0b013e3282f62c89.

Abstract

Cocaine-associated cues can elicit incentive motivational effects that drive cocaine-seeking behavior and contribute to relapse. The extinction/reinstatement model is commonly used to measure these effects in animals. This study examined the influence of training and testing schedules of reinforcement on cue-elicited reinstatement. Lever presses during training resulted in cues and cocaine (0.75 mg/kg/IV) on either continuous or partial reinforcement schedules [fixed ratio (FR) 1 or 11, variable ratio (VR) 5 or 11]. Animals then underwent extinction training, followed by a test for cue-elicited reinstatement of extinguished cocaine-seeking behavior by response-contingent cue presentations on either a continuous (FR 1) or a partial reinforcement schedule (FR 11). Partial reinforcement during training resulted in higher response rates during cue-elicited reinstatement relative to continuous reinforcement. In contrast, delivery of cues on a continuous reinforcement schedule during testing yielded higher response rates relative to delivery on a partial reinforcement schedule. Finally, the shift from a partial to a continuous reinforcement schedule across training and testing phases did not alter response rates. These findings provide important information for choosing parameters for reinstatement of drug-seeking behavior that would allow the most sensitive method to detect changes in response rate after an experimental manipulation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cocaine / administration & dosage*
  • Cocaine-Related Disorders / psychology*
  • Cues*
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Extinction, Psychological / drug effects
  • Male
  • Motivation*
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement Schedule*
  • Self Administration

Substances

  • Cocaine