title: Unidirectional relationship between heroin self-administration and impulsive decision-making in rats.
abstract: BACKGROUND
  There is growing clinical evidence for a strong relationship between drug addiction and impulsivity. However, it is not fully clear whether impulsivity is a pre-existing trait or a consequence of drug abuse. Recent observations in the animal models show that pre-existing levels of impulsivity predict cocaine and nicotine seeking. Whether such relationships also exist with respect to non-stimulant drugs is largely unknown.
  
  
  OBJECTIVE
  We studied the relationship between impulsive choice and vulnerability to heroin taking and seeking.
  
  
  METHODS
  Rats were selected in the delayed reward task based on individual differences in impulsive choice. Subsequently, heroin intravenous self-administration behaviour was analysed, including acquisition of heroin intake, motivation, extinction and drug- and cue-induced reinstatement. Throughout the entire experiment, changes in impulsive choice were monitored weekly.
  
  
  CONCLUSIONS
  High impulsivity did not predict measures of heroin taking. Moreover, high impulsive rats did not differ from low impulsive rats in extinction rates or heroin- and cue-induced reinstatement. However, both groups became more impulsive as heroin self-administration continued. During abstinence, impulsivity levels returned towards baseline (pre-heroin) levels. Our results indicate that, in contrast to psychostimulants, impulsive choice does not predict vulnerability to heroin seeking and taking.
  
  
  CONCLUSIONS
  These data implicate that different neural mechanisms may underlie the vulnerability to opiate and psychostimulant dependence. Moreover, our data suggest that elevated impulsivity levels as observed in heroin-dependent subjects are a consequence of heroin intake rather than a pre-existing vulnerability trait.
authors: Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, Vrije Universiteit University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. r.schippers@vumc.nl
authors: Maria C
authors: MC
authors: Schippers
authors: Rob
authors: R
authors: Binnekade
authors: Anton N M
authors: AN
authors: Schoffelmeer
authors: Tommy
authors: T
authors: Pattij
authors: Taco J
authors: TJ
authors: De Vries
mesh_terms: D000818:Animals; D002755:Choice Behavior / Q000187:drug effects; D003463:Cues; D003657:Decision Making / Q000187:drug effects*; D058999:Drug-Seeking Behavior / Q000187:drug effects; D005108:Extinction, Psychological / Q000187:drug effects; D003932:Heroin / Q000008:administration & dosage / Q000494:pharmacology*; D007175:Impulsive Behavior / Q000139:chemically induced*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012201:Reward; D012646:Self Administration
chemical_list: D003932:Heroin