Age-Related Differences And Role Of Novelty In The Expression Of Ethanol-Induced Locomotor Activation

ACEVEDO MB; PAUTASSI RM

Huerta Grande, Cba

Congreso; IIRCN, Second Joint Meeting of the Argentine Society for Neurosciences (SAN) and the Argentine Workshop in Neurosciences (TAN); 2010

Argentine Society for Neurosciences (SAN) and the Argentine Workshop in Neurosciences (TAN)

AGE-RELATED DIFFERENCES AND ROLE OF NOVELTY IN THE EXPRESSION OF ETHANOL-INDUCED LOCOMOTOR ACTIVATION   Adolescent rats exhibit ethanol-induced locomotor activity (Acevedo et al., 2010). Spontaneous and ethanol-induced activation in an inescapable environment have been hypothesized to predict ethanol reinforcement and self-administration. This work assessed age-related differences in ethanol’s motor stimulating effects and analyzed the role of novelty in the expression of these effects. Adolescent (postnatal days, PD28) and adult rats (PD70) were given ethanol (0.0 or 2.5 g/kg; i.g.) and screened for motor activation in an open field, during post-intubation minutes 5 to 11. A subsequent experiment assessed ethanol-induced activity in adolescent rats that had been previously habituated to the open field.  Ethanol induced motor activating effects and this result was similar for adolescents and adults (Experiment 1). Repeated exposure to the test arena caused a significant decrease in locomotion in vehicle-treated adolescents, a result suggestive of habituation to the context. The adolescents given ethanol, however, exhibited robust behavioral stimulation even when the test arena was no longer novel (Experiment 2). These results indicate that adolescent and adult animals appear to perceive the pharmacological effects of high-dose ethanol as similarly activating. Ethanol-induced locomotor activity in adolescents does not depend on the novelty of the testing environment.