Heroin self-administration: I. Incubation of goal-directed behavior in rats

Pharmacol Biochem Behav. 2008 Sep;90(3):344-8. doi: 10.1016/j.pbb.2008.03.018. Epub 2008 Apr 3.

Abstract

This study used heroin self-administration to investigate incubation of goal-directed heroin-seeking behavior following abstinence. Male Sprague-Dawley rats self-administered heroin on a fixed ratio 10 (FR10) schedule of reinforcement with licking of an empty spout serving as the operant behavior during 14 daily 3 h sessions. After this acquisition period, all rats received a 90 min extinction session following either 1 day or 14 days of home cage abstinence. When the extinction session occurred after only 1 day of home cage abstinence, rats with a history of heroin self-administration divided their responses equally between the previously "active" and "inactive" spouts. However, when the extinction session occurred following 14 days of home cage abstinence, the rats exhibited marked goal-directed heroin-seeking behavior by licking more on the previously "active" than "inactive" spout. These findings demonstrate that heroin-seeking behavior incubates over time, resulting in goal-directed heroin-seeking behavior in rats following 14 days but not 1 day of abstinence. Moreover, this facilitatory effect occurred in response to a different training schedule, lower total drug intake, and shorter periods of daily access than previously reported with heroin.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Conditioning, Operant / drug effects*
  • Extinction, Psychological / drug effects
  • Goals*
  • Heroin / administration & dosage
  • Heroin / pharmacology
  • Heroin Dependence / psychology*
  • Male
  • Narcotics / administration & dosage
  • Narcotics / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement Schedule
  • Self Administration
  • Substance Withdrawal Syndrome / psychology
  • Water Deprivation

Substances

  • Narcotics
  • Heroin