The explicit intention of this study was to test, in adolescent and adult rats, ethanol reinforcement (preference or aversion) using a similar SOC procedure. To provide supplementary evidence relevant to possible first-order conditioned responses, behavioral reactivity to CS1 (locomotor activity, wall climbing and head shaking) was assessed during the second-order conditioning phase. Brain and blood ethanol levels (BrELs and BELs, respectively) associated with the behavioral expression of ethanol’s effects in both age groups were examined in a separate group of animals. Levels attained in blood and brain were measured at postadministration intervals representing the onset of each conditioning phase (7.5 and 32.5 min).
