Psychopharmacology

, Volume 186, Issue 1, pp 82–92

Effects of dexfenfluramine and 5-HT3 receptor antagonists on stress-induced reinstatement of alcohol seeking in rats

Authors

    • Department of NeuroscienceCentre for Addiction and Mental Health
    • Department of PharmacologyUniversity of Toronto
    • Department of PsychiatryUniversity of Toronto
  • Douglas Funk
    • Department of NeuroscienceCentre for Addiction and Mental Health
  • Stephen Harding
    • Department of NeuroscienceCentre for Addiction and Mental Health
  • W. Juzytsch
    • Department of NeuroscienceCentre for Addiction and Mental Health
  • Paul J. Fletcher
    • Department of NeuroscienceCentre for Addiction and Mental Health
    • Department of PsychiatryUniversity of Toronto
    • Department of PsychologyUniversity of Toronto
  • Yavin Shaham
    • Behavioral Neuroscience BranchIRP/NIDA/NIH/DHHS
Original Investigation

DOI: 10.1007/s00213-006-0346-y

Cite this article as:
Lê, A.D., Funk, D., Harding, S. et al. Psychopharmacology (2006) 186: 82. doi:10.1007/s00213-006-0346-y

Abstract

Rationale and objectives

We previously found that systemic injections of the 5-HT uptake blocker fluoxetine attenuate intermittent footshock stress-induced reinstatement of alcohol seeking in rats, while inhibition of 5-HT neurons in the median raphe induces reinstatement of alcohol seeking. In this study, we further explored the role of 5-HT in footshock stress-induced reinstatement of alcohol seeking by determining the effects of the 5-HT releaser and reuptake blocker dexfenfluramine, and the 5-HT receptor antagonists ondansetron and tropisetron, which decrease alcohol self-administration and anxiety-like responses in rats, on this reinstatement.

Methods

Different groups of male Wistar rats were trained to self-administer alcohol (12% v/v) for 28–31 days (1 h/day, 0.19 ml per alcohol delivery) and then their lever responding for alcohol was extinguished over 9–10 days. Subsequently, the effect of systemic injections of vehicle or dexfenfluramine (0.25 or 0.5 mg/kg, i.p), ondansetron (0.001, 0.01, or 0.1 mg/kg, i.p), or tropisetron (0.001, 0.01, and 0.1 mg/kg, i.p) on reinstatement induced by 10 min of intermittent footshock (0.8 mA) was determined.

Results

Systemic injections of dexfenfluramine, ondansetron or tropisetron attenuated footshock-induced reinstatement of alcohol seeking. Injections of dexfenfluramine, ondansetron, or tropisetron had no effect on extinguished lever responding in the absence of footshock.

Conclusions

The present results provide additional support for the hypothesis that brain 5-HT systems are involved in stress-induced reinstatement of alcohol seeking. The neuronal mechanisms that potentially mediate the unexpected observation that both stimulation of 5-HT release and blockade of 5-HT3 receptors attenuate footshock-induced reinstatement are discussed.

Keywords

5-HydroxytryptamineReinstatementFootshock5-HT3 receptorsRelapseStress

Copyright information

© Springer-Verlag 2006