Locomotor activity predicts acquisition of self-administration behavior but not cocaine intake

Behav Neurosci. 2005 Apr;119(2):464-72. doi: 10.1037/0735-7044.119.2.464.


The current study investigates locomotor activity in a novel environment and correlates these activity levels with cocaine self-administration in rats that were either trained or untrained on a lever-pressing task prior to cocaine self-administration. The authors report that it is the rate of learning the lever-pressing task, not cocaine self-administration, that correlates with locomotor activity. The results suggest that a correlation between locomotor activity and cocaine self-administration is secondary to a link between locomotor activity and rate of learning to lever press for a reward. The authors conclude that locomotor activity is not necessarily an indicator of propensity to self-administer cocaine and demonstrate that environmental novelty and rate of learning an operant task are important considerations when designing experiments on drug-seeking behaviors.

Publication types

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

MeSH terms

  • Animals
  • Cocaine / administration & dosage*
  • Cocaine / pharmacology*
  • Conditioning, Operant*
  • Dopamine Uptake Inhibitors / administration & dosage*
  • Dopamine Uptake Inhibitors / pharmacology*
  • Exploratory Behavior*
  • Learning
  • Male
  • Motor Activity*
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement, Psychology
  • Self Administration


  • Dopamine Uptake Inhibitors
  • Cocaine