Acceso usuarios
Agustín Salguero, Victoria Mujica, Leandro Ruiz Leyva, Ignacio Morón Henche, Cruz Miguel Cendán Martínez, Leonardo Gabriel Marengo, Paloma Moreno, Ricardo Marcos Pautassi
Introduction:Previous studies suggest that the Sigma receptor system is involved in the motivational effects of ethanol. Objective:we examined, in adolescent rats, the involvement of the sigma 1 receptor (S1-R) antagonist S1RA in an ethanol-induced conditioned taste aversion (CTA). Methods: we studied the role of S1RA in an ethanol-induced CTA in which the Conditioned Stimulus (CS, saccharine, 0.1%) was presented immediately before the Unconditioned Stimulus (US, ethanol, 2.5 g/kg) or with a CS-US interval of 30 minutes. Results:In Experiment 1we found that administration of S1RA (4 or 16 mg/kg, administered 30 min before alcohol) did not alter the expression or extinction of ethanol-induced CTA. A second phase of this experiment tested control rats (i.e., those administered with 0 g/kg alcoholat the previous phase) for lithium-chloride–induced CTA (like in the previous phase, the CS was presented immediately before the US), which was not affected by S1RA (16 mg/kg). In Experiment 2 we inserted a 30 min interval between CS and US, and this resulted in the absence of ethanol-induced CTA. Administration of S1RA (16 mg/kg) before alcohol, however, promoted the expression of this long-trace ethanol-induced CTA at adolescence. Intriguingly, we found that rats given S1RA at conditioning (PD30) did notexhibit ethanol-induced locomotor activity, when assessed later at adolescence (PD39). Administration of S1RA (16 mg/kg) did not affect mean alcohol blood levels at PD30. Discussion:These results suggest that S1-R antagonism, at adolescence, might block the appetitive effects of ethanol and, therefore, exacerbate the aversive effects of this drug.
