Attention, impulsivity, and cognitive flexibility in adult male rats exposed to ethanol binge during adolescence as measured in the five-choice serial reaction time task: the effects of task and ethanol challenges

Abstract

Alcohol abuse is prevalent in adolescent humans, but the long-term behavioral consequences of binge alcohol drinking are unknown. This study investigated the long-term effects of adolescent intermittent ethanol (AIE) exposure on attention and impulsivity. Adolescent male rats were exposed to 5 g/kg of 25% (v/w) ethanol every 8 h for 4 days. During adulthood, rats were tested in the five-choice serial reaction time task (5-CSRTT) assessing attention, impulsivity and cognitive flexibility. There was no metabolic tolerance to ethanol in adolescent rats during AIE exposure. In the 5-CSRTT under baseline conditions, there were no differences between AIE-exposed and control rats in accuracy, omissions, or premature responses, although AIE-exposed rats tended to make more timeout responses than control rats. The short-duration stimulus challenge decreased accuracy and increased omissions and timeout responses in both AIE-exposed and control rats. The long intertrial interval challenge increased premature responses in all rats. An ethanol challenge decreased correct responses, and increased omissions in control, but not in AIE-exposed, rats. Control, but not AIE-exposed, rats exhibited decreased premature and timeout responses after ethanol administration. Response latencies were not affected in AIE-exposed or control rats indicating no sedative effects of ethanol challenge. The results indicate that ethanol binge exposure during adolescence has long-lasting neurobehavioral consequences, which persist into adulthood and can be revealed after re-exposure to ethanol. AIE-induced diminished responses to the disruptive effects of ethanol on attention, impulsivity and cognitive flexibility may lead to increased alcohol drinking and other maladaptive behaviors in adulthood.