Estudo do papel da oxitocina sobre os efeitos do etanol em camundongos adolescentes: comportamento de consumo, atividade locomotora e ansiedade

Abstract

The brain remains developing during adolescence, a period of vulnerability to ethanol use. It was recently described that there is expression of oxytocin receptors in the circuitry associated with ethanol dependence. As we believe that adolescence is a fundamental period for intervention in drug addiction, in the present study we studied the therapeutic potential of intranasal oxytocin in a model of ethanol dependence during adolescence and its behavioral effects. In this study we evaluate the effect of oxytocin administration (100 µg/kg, intranasally, 1 hour before the test) on the effects of ethanol on locomotor activity (4mg/Kg, gavage) in the open field test (OF) and in anxiety-like behavior (2 mg/kg, gavage) in the elevated plus-maze test (EPM), and ethanol consumption in a two bottle choice test (10% v/v solution) in adolescent Swiss mice. The consumption (10% v/v) was evaluated during 3 hours after the beginning of the dark period for five consecutive days. In this case, half of the animals were exposed previously to the ethanol solution in the drinking water for five days followed by two days of abstinence. Our data indicate that the administration of oxytocin promoted an increase in locomotor activity in OF as well as the administration of ethanol. The co-exposure heightened this effect. In EPM, exposure to ethanol generated an anxiolytic response. This effect was reversed by co-exposure with oxytocin. In addition, oxytocin reduced ethanol consumption, especially after a few days of administration. Taken together, our findings indicate that the activation of the oxytocinergic system promotes an additive action to the psychostimulant effects and reduces the anxiolytic effects of ethanol and may result in a reduction in its consumption in adolescent animals.