A behavioral phenotype detected early in development can predict the sensitivity to the stimulating effect of ethanol

CARTELLO, S.; REVILLO, D.A.; ARIAS, C.; MOLINA, J.C.

Congreso; Sociedad Argentina de Neurociencias; 2012

Sociedad Argentina de Neurociencias

Relatively high ethanol doses (between 1.25 and 2.5 g/kg) induce acute locomotor stimulating effects in preweanling rats, an effect associated with the rewarding properties of the drug. Baseline locomotor activity predicts the magnitude of this ethanol effect in infant and adult rats. The goals of the present work were to analyze whether repeated ethanol exposure results in conditioned sensitization or tolerance of the locomotor stimulating effect, and whether a behavioral phenotype based on the initial exploration of an environment during the first postnatal week of life can predict a long-term response to ethanol. Baseline locomotor activity was registered on postnatal day 8 (PD 8). Then, subjects (PDs 8 to 12) received 0 or 2.5 g/kg ethanol before being placed in an open field containing an odor cue. On PD 15 pups were tested in an open field after being injected with ethanol (0 or 2.5 g/kg) in presence or absence of the odor. Results showed ethanol induced locomotor activating effects in infant rats (between PD8 and PD15). Repeated exposure to the drug did not induce tolerance when pups were tested in absence of the odor cue, but when the odor was present there were some evidences of conditioned tolerance to the stimulating effect. Besides, baseline level of activity (on PD 8) predicted ethanol response on PD 15, independently of the presence of the odor cue. These results suggest the possibility to use early behavioral markers to predict unconditioned effects of ethanol.