High impulsivity predicting vulnerability to cocaine addiction in rats: some relationship with novelty preference but not novelty reactivity, anxiety or stress

Psychopharmacology (Berl). 2011 Jun;215(4):721-31. doi: 10.1007/s00213-011-2167-x. Epub 2011 Jan 28.


Rationale: Impulsivity is a vulnerability marker for drug addiction in which other behavioural traits such as anxiety and novelty seeking ('sensation seeking') are also widely present. However, inter-relationships between impulsivity, novelty seeking and anxiety traits are poorly understood.

Objective: The objective of this paper was to investigate the contribution of novelty seeking and anxiety traits to the expression of behavioural impulsivity in rats.

Methods: Rats were screened on the five-choice serial reaction time task (5-CSRTT) for spontaneously high impulsivity (SHI) and low impulsivity (SLI) and subsequently tested for novelty reactivity and preference, assessed by open-field locomotor activity (OF), novelty place preference (NPP), and novel object recognition (OR). Anxiety was assessed on the elevated plus maze (EPM) both prior to and following the administration of the anxiolytic drug diazepam, and by blood corticosterone levels following forced novelty exposure. Finally, the effects of diazepam on impulsivity and visual attention were assessed in SHI and SLI rats.

Results: SHI rats were significantly faster to enter an open arm on the EPM and exhibited preference for novelty in the OR and NPP tests, unlike SLI rats. However, there was no dimensional relationship between impulsivity and either novelty-seeking behaviour, anxiety levels, OF activity or novelty-induced changes in blood corticosterone levels. By contrast, diazepam (0.3-3 mg/kg), whilst not significantly increasing or decreasing impulsivity in SHI and SLI rats, did reduce the contrast in impulsivity between these two groups of animals.

Conclusions: This investigation indicates that behavioural impulsivity in rats on the 5-CSRTT, which predicts vulnerability for cocaine addiction, is distinct from anxiety, novelty reactivity and novelty-induced stress responses, and thus has relevance for the aetiology of drug addiction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Anxiety Agents / administration & dosage
  • Anti-Anxiety Agents / therapeutic use
  • Anxiety / blood
  • Anxiety / prevention & control
  • Anxiety / psychology*
  • Cocaine-Related Disorders / blood
  • Cocaine-Related Disorders / prevention & control
  • Cocaine-Related Disorders / psychology*
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology
  • Corticosterone / blood
  • Diazepam / administration & dosage
  • Diazepam / therapeutic use
  • Exploratory Behavior* / drug effects
  • Impulsive Behavior / blood
  • Impulsive Behavior / prevention & control
  • Impulsive Behavior / psychology*
  • Male
  • Maze Learning / drug effects
  • Maze Learning / physiology
  • Motor Activity / drug effects
  • Motor Activity / physiology
  • Predictive Value of Tests
  • Rats
  • Rats, Inbred Strains
  • Stress, Psychological / blood
  • Stress, Psychological / prevention & control
  • Stress, Psychological / psychology*


  • Anti-Anxiety Agents
  • Diazepam
  • Corticosterone