Fig. 5.

Adolescent intermittent ethanol (AIE) treatment impairs reversal learning and increases risky decision-making in adulthood. a From postnatal day (P)25 to P55, AIE-treated male Wistar rats received a single daily intragastric (i.g.) dose of ethanol (5.0 g/kg, 20% ethanol, w/v) on a 2-day on/off schedule, and CON subjects received comparable volumes of water as previously described (Vetreno and Crews 2012). Following a 25-day abstinence period, spatial and reversal learning were assessed on the Barnes maze. While AIE treatment did not impair spatial learning, reversal learning, which provides a measure of behavioral flexibility, was impaired in adulthood as evidenced by increased latency to the reversal goal and increased perseveration. Following behavioral testing, brain tissue was collected and tissue stained for innate immune markers. Expression of toll-like receptor 4 (TLR4) was positive correlated with latency to the reversal goal, indicating that innate immune induction by AIE contributes to deficits in adult deficits in behavioral flexibility. Adopted from Vetreno and Crews (2012). Data are presented as mean ± SEM. *p < 0.05. b From P28 to P53, male Wistar rats received three daily i.g. doses of ethanol (5.0 g/kg, 25% ethanol, w/v) on a 2-day on/off schedule, and CON subjects received comparable volumes of water. Following an abstinent period on P63, training and testing were performed on the probability-discounting task. Prior AIE treatment significantly increased risky responses at reducing reward probabilities, relative to CON subjects. Expression of choline acetyltransferase (ChAT), a marker of cholinergic neurons, was reduced in the basal forebrain of adult AIE-treated animals that was negatively correlated with probability-discounting behavior. Adopted from Markou and colleagues (Boutros et al. 2015). Data are presented as mean ± SEM. *p < 0.05