SOCIAL ISOLATION ENHANCES ETHANOL-MEDIATED LOCOMOTOR STIMULATION IN PREWEANLING RATS

SOLARI, A.C.; ARIAS, C.; HAYMAL, B; MOLINA, J.C.

Huerta-Grande

Congreso; Sociedad Argentina de Neurociencias; 2009

Sociedad Argentina de Neurociencias

Preweanling rats are highly sensitive to the locomotor stimulation induced by relatively high ethanol doses. In adult mice this ethanol (EtOH) effect is modulated by stress. The goals of the present study were to analyze a) whether EtOH-mediated stimulation is enhanced under acute stress in preweanling rats, and b) the role of corticosterone (cort) related to this ethanol effect. Stress was induced by means of a social isolation treatment known to enhance basal cort levels. In Exp1, four hours before ethanol administration (0 or 2.5 g/kg) preweanling rats were isolated or remained in their homecage. In Exp 2 ethanol-mediated locomotor activation was assessed in adrenalectomized pups (appropiate sham controls were included in the design). In Exp3 pups were given 0, 3 or 6 mgkg cort before ethanol administration.. The dependent variable in all the experimients was locomotor activity (measured 5-10 and 35-40 minutes after ethanol administration). Social stress strongly enhanced ethanolmediated locomotor stimulation but had no effect on locomotor acivity patterns in water-treated controls. (Exp 1). Adrenalectomized pups did not differ from controls in terms of locomotor activity induced by ethanol (Exp 2), and exogenous cort did not to enhance ethanol-mediated activation (Exp 3). These results demostrate that stress modulates ethanol locomotor effects in early stages of development. Additionally, the interaction between stress and ethanol upon locomotor stimulation is independent from cort activity.