Open field exposure at training enhances ethanol-induced conditioned taste aversion

JUSTEL N; PAUTASSI R.M.; PSYRDELLIS M; SALGUERO, A.

San Luis

Congreso; 2 Congreso Nacional de Psicología; 2019

Universidad Nacional de San Luis

Introduction: The aversive motivational effects of ethanol significantly modulate the initiation and escalation of ethanol use, and can be measured using the conditioned taste aversion (CTA) preparation. CTA is defined by a reduction in the intake of a flavor, such as saccharine, after a pairing of the flavor with a known aversive agent, such as ethanol. Thus, the animal associates the aversive pharmacological consequences of the drug with the taste. Novelty exposure, operationalized by an open field (OF) exploration, can modulate aversive memories and responsiveness to aversive stimulation. Objective: the aim of this study was to asses if OF exposure modulates the expression of ethanol-induced CTA in rats. Methodology: Experiment 1 employed 30 male, adult Wistar, rats divided in three groups according to the dose of ethanol that they received (0.0, 0.75 and 1.25g/kg). Experiment 2 employed 42 male, adult Wistars, distributed in a 2 (Treatment: OF vs CONTROL) x 2 (Ethanol: 0.0 vs 1.25g/kg) factorial design. Results: The first experiment probed different doses of the unconditioned stimulus and found that a 1.25 g/kg, but not a 0.75 g/kg, ethanol dose induced a reliable conditioned taste aversion to saccharine. In Experiment 2, the experimental group explored an OF for 5 min, one hour before the pairing between saccharine and the pharmacological effects of ethanol, while the control group remained in their homecage. The results indicated that novelty exacerbated the ethanol-induced conditioned taste aversion to saccharine. Conclussion: OF exposure significantly modulated the expression of ethanol-induced CTA. Exposure to the OF 60 min before the pairing of the taste (conditioned stimulus) and ethanol?s unconditional effects resulted in an enhancement of the ethanol-induced aversive learning. Discussion: this data suggest that exposure to novelty represents a simple, yet valuable behavioral treatment to augment the aversive effects of alcohol, which has important implications. Blunted responsivity to ethanol-induced CTA in adolescent, when compared to adult, rats is associated with heightened ethanol intake in two-bottle free choice tests. On the other hand, increased ethanol-induced CTA is associated with protection from alcohol use. Therefore, behavioral interventions that augment ethanol-induced aversion may have clinical applications.