Naloxone Facilitates Extinction but Does Not Affect Acquisition or Expression of Ethanol-Induced Conditioned Place Preference

Christopher L. Cunningham, Shelly D. Dickinson, Dobrina M. Okorn

Research output: Contribution to journalArticle

47 Scopus citations


Mice (DBA/2J) received a Pavlovian procedure in which a distinctive floor stimulus was paired 4 times with ethanol (2 g/kg). A different floor stimulus was paired with saline. Naloxone (0.0, 1.5, or 10.0 mg/kg, intraperitoneal) given before each ethanol trial did not interfere with acquisition of conditioned preference, although naloxone alone produced conditioned aversion. When naloxone (0.0, 0.15, 1.5, 3.0, or 10.0 mg/kg) was given for the first time during testing, mice showed conditioned preference during the first 10 min. However, preference subsequently decreased dose-dependently over time. Control studies eliminated alternative interpretations based on pharmacokinetics or presence of an aversive state. The overall pattern of results suggests that naloxone facilitated extinction of conditioned place preference and supports the hypothesis that ethanol-induced conditioned reinforcement is mediated by the endogenous opioid system.

Original languageEnglish (US)
Pages (from-to)330-343
Number of pages14
JournalExperimental and Clinical Psychopharmacology
Issue number4
StatePublished - Nov 1995


ASJC Scopus subject areas

  • Pharmacology
  • Psychiatry and Mental health
  • Pharmacology (medical)

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