Effect of low doses of delta9-tetrahydrocannabinol and cannabidiol on the extinction of cocaine-induced and amphetamine-induced conditioned place preference learning in rats

Psychopharmacology (Berl). 2004 Sep;175(3):360-6. doi: 10.1007/s00213-004-1825-7.


Rationale: Using the place-preference conditioning paradigm, we evaluated the potential of the two most prominent cannabinoids found in marijuana, the psychoactive component delta9-tetrahydrocannabinol (delta9-THC) and the nonpsychoactive component cannabidiol (CBD), to potentiate extinction of a cocaine-induced and an amphetamine-induced conditioned place preference in rats.

Methods: To determine the effects of pretreatment with delta9-THC or CBD on extinction, a cocaine-induced and amphetamine-induced place preference was first established. Rats were then given an extinction trial, during which they were confined to the treatment-paired floor for 15 min. Thirty minutes prior to the extinction trial, they were injected with a low dose of delta9-THC (0.5 mg/kg), CBD (5 mg/kg) or vehicle. The potential of the CB1 receptor antagonist, SR141716, to reverse the effects of delta9-THC or CBD was also evaluated. To determine the hedonic effects of CBD, one distinctive floor was paired with CBD (5 mg/kg) and another with saline. Finally, to determine the effect of delta9-THC.or CBD on the establishment and/or the expression of a place preference during four cycles of conditioning trials, rats were injected with delta9-THC (0.25-1 mg/kg), CBD (5 mg/kg) or vehicle 25 min prior to receiving an injection of amphetamine followed by placement on the treatment floor; on alternate days, they received injections of vehicle followed by saline and placement on the nontreatment floor. The rats then received two test trials; on one trial they were pretreated with the cannabinoid and on the other trial with vehicle.

Results: delta9-THC and CBD potentiated the extinction of both cocaine-induced and amphetamine-induced conditioned place preference learning, and this effect was not reversed by SR141716. The cannabinoids did not affect learning or retrieval, and CBD was not hedonic on its own.

Conclusions: These results are the first to show that both delta9-THC, which acts on both CB 1 and CB2 receptors, and CBD, which does not bind to CB1 or CB2 receptors, potentiate the extinction of conditioned incentive learning.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amphetamine / pharmacology*
  • Animals
  • Cannabidiol / pharmacology*
  • Cocaine / pharmacology*
  • Conditioning, Operant
  • Dronabinol / pharmacology*
  • Extinction, Psychological / drug effects*
  • Learning / drug effects*
  • Male
  • Piperidines / pharmacology
  • Pyrazoles / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Cannabinoid, CB1 / antagonists & inhibitors
  • Rimonabant


  • Piperidines
  • Pyrazoles
  • Receptor, Cannabinoid, CB1
  • Cannabidiol
  • Dronabinol
  • Amphetamine
  • Cocaine
  • Rimonabant