Absence of cocaine-induced place conditioning in serotonin 1B receptor knock-out mice

Pharmacol Biochem Behav. 2000 May;66(1):221-5. doi: 10.1016/s0091-3057(00)00238-0.


A large body of evidence suggests that genetic factors may affect the reinforcing properties of drugs of abuse. This study investigated the involvement of the serotonin 1B (5-HT1B) receptor in modulating cocaine-induced place conditioning by comparing the response of 5-HT1B receptor gene knock-out mice with wild type 129/Sv-ter mice. The rewarding effects of various doses of cocaine (0, 2.5, 5, 10, 20, and 40 mg/kg) were examined in both strains. Results clearly show that 5-HT1B receptor knock-out mice failed to display a conditioned place preference for stimuli paired with cocaine while wild type mice exhibited a conditioned place preference for the compartment paired with cocaine (5 and 20 mg/kg). As other studies showed that 5-HT1B knock-out mice self-administer cocaine, these results suggest a dissociation between the psychologic state linked to self-administration and the one measured in conditioned place preference.

MeSH terms

  • Animals
  • Cocaine / pharmacology*
  • Conditioning, Psychological / drug effects*
  • Male
  • Mice
  • Mice, Knockout
  • Receptor, Serotonin, 5-HT1B
  • Receptors, Serotonin / genetics
  • Receptors, Serotonin / physiology*


  • Receptor, Serotonin, 5-HT1B
  • Receptors, Serotonin
  • Cocaine