Stimulus properties of venlafaxine in a conditioned taste aversion procedure

Eur J Pharmacol. 2008 Oct 31;596(1-3):102-6. doi: 10.1016/j.ejphar.2008.08.015. Epub 2008 Aug 29.

Abstract

Conditioned stimulus properties of venlafaxine are still unknown. In the present study, the discriminative stimulus properties of venlafaxine by using a conditioned taste aversion procedure were investigated. Swiss Webster mice were allowed to reach water from 2 pipettes for 20 min (09:00-11:30 h), plus 30 min (15:30-16:00 h), daily. During the 4 days, the test drugs [fluoxetine, escitalopram, tianeptine, reboxetine, and Nomega-nitro-L-arginine methyl ester (L-NAME)] were injected to mice at least 1 h after they had first water session. On day 5, they consumed glucose solution (5% w/v) and immediately injected with conditioning drug (venlafaxine 32 mg/kg). On day 8, mice were allowed to make a choice between water and glucose solution. The amount of glucose consumption as a percentage of total fluid intakes was calculated for each animal. Significant reduction in glucose choice was defined as conditioned taste aversion. Venlafaxine (32 mg/kg) induced a robust conditioned taste aversion in mice. Pre-exposure to tianeptine (2.5-10 mg/kg), fluoxetine (10 mg/kg), escitalopram (32 mg/kg), and reboxetine (5 mg/kg) substituted for venlafaxine by preventing the conditioned taste aversion induced by venlafaxine. L-NAME did not substitute for venlafaxine. Substitution of venlafaxine by fluoxetine, tianeptine, escitalopram, and reboxetine provides further evidence that both 5-HT and noradrenaline reuptake inhibition may play an important role in the stimulus effect of venlafaxine.

MeSH terms

  • Adrenergic Uptake Inhibitors / pharmacology*
  • Animals
  • Antidepressive Agents / pharmacology*
  • Avoidance Learning / drug effects*
  • Conditioning, Psychological / drug effects*
  • Cyclohexanols / pharmacology*
  • Male
  • Mice
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / physiology
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Selective Serotonin Reuptake Inhibitors / pharmacology*
  • Taste*
  • Venlafaxine Hydrochloride

Substances

  • Adrenergic Uptake Inhibitors
  • Antidepressive Agents
  • Cyclohexanols
  • Serotonin Uptake Inhibitors
  • Nitric Oxide
  • Venlafaxine Hydrochloride
  • Nitric Oxide Synthase
  • NG-Nitroarginine Methyl Ester