Original Investigation

Psychopharmacology

, Volume 195, Issue 3, pp 345-355

The CRF1 receptor antagonist antalarmin attenuates yohimbine-induced increases in operant alcohol self-administration and reinstatement of alcohol seeking in rats

  • Peter W. MarinelliAffiliated withDepartment of Neuroscience, Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental HealthDepartment of Neurosciences, CAMH Email author 
  • , Douglas FunkAffiliated withDepartment of Neuroscience, Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health
  • , Walter JuzytschAffiliated withDepartment of Neuroscience, Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health
  • , Stephen HardingAffiliated withDepartment of Neuroscience, Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health
  • , Kenner C. RiceAffiliated withDepartment of Health and Human Services, National Institutes of Health, National Institute on Drug Abuse, Intramural Research Program
  • , Yavin ShahamAffiliated withDepartment of Health and Human Services, National Institutes of Health, National Institute on Drug Abuse, Intramural Research Program
  • , A. D. LêAffiliated withDepartment of Neuroscience, Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental HealthDepartment of Pharmacology, University of TorontoDepartment of Psychiatry, University of Toronto

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Abstract

Rationale and objectives

Yohimbine is an alpha-2 adrenoreceptor antagonist that provokes stress- and anxiety-like responses in both humans and laboratory animals. In rats, yohimbine increases operant alcohol self-administration and reinstates alcohol seeking. In this study, we assess whether these effects of yohimbine are attenuated by systemic injections of the corticotrotropin-releasing factor 1 (CRF1) receptor antagonist antalarmin.

Materials and methods

In Exp. 1, we trained rats to lever press for alcohol solutions (12% w/v, 1 h/day) over several weeks; during training, the response requirement was increased from a fixed-ratio-1 (FR-1) to a fixed-ratio-3 (FR-3) reinforcement schedule. We then tested the effect of antalarmin (10 or 20 mg/kg) on yohimbine (1.25 mg/kg)-induced increases in operant alcohol self-administration (FR-3 reinforcement schedule). Subsequently, we assessed the effect of antalarmin on yohimbine-induced increases in plasma corticosterone levels in the previously self-administering rats. In Exp. 2, we trained the rats to self-administer alcohol as in Exp. 1, and after extinction of the alcohol-reinforced lever responding over 13 days, we tested antalarmin’s effect on yohimbine-induced reinstatement of alcohol seeking.

Results

Yohimbine increased operant alcohol self-administration and reinstated alcohol seeking after extinction. These effects of yohimbine were attenuated by antalarmin. Antalarmin injections in the absence of yohimbine had no effect on either operant alcohol self-administration or extinction responding. Antalarmin had no effect on yohimbine-induced corticosterone release in alcohol-experienced rats.

Conclusions

These results suggest that extrahypothalamic CRF1 receptors are involved in the effect of yohimbine on operant alcohol self-administration and on relapse to alcohol seeking and support the notion that CRF1 receptor antagonists should be considered in alcohol addiction treatment.

Keywords

Alcohol self-administration Alpha-2 adrenoceptors Corticosterone CRF CRF1 receptor Relapse Reinstatement Stress Noradrenaline