Environmental enrichment during adolescence heightens ethanol intake in female, but not male, adolescent rats that are selectively bred for high and low ethanol intake during adolescence

SUAREZ, ANDREA; FABIO, MARÍA CAROLINA; BELLIA, FABIO; MS FERNÁNDEZ; PAUTASSI, R.M.

The American Journal of Drug and Alcohol Abuse

Taylor and Francis Ltd

Año: 2020 vol. 46 p. 553 - 564

0095-2990

Background: Discriminating between adolescents who will eventually have ethanol use problems from those who do not is important. Environmental enrichment is a promising approach to reduce drug-related problems, but its impact on ethanol?s effects and intake is being scrutinized. Objective: We tested the effects of environmental enrichment on ethanol intake, preference, and anxiety-like response as well as shelter seeking and risk-taking behaviors. Experiment 1 examined ethanol intake, preference, and anxiety-like responses in 46 male and 54 female Wistar rats that were derived from a short-term breeding program that selected for high and low ethanol drinking during adolescence (ADHI2 and ADLO2 lines, respectively). Shelter-seeking and risk-taking behaviors were assessed (Experiment 2) in ADHI2 and ADLO2 rats (73 males, 76 females) reared under environmental enrichment or standard housing conditions and given doses of ethanol (2.5 g/kg, intraperitoneal) for 3 weeks. Methods: Environmental enrichment was applied on postnatal days 21-42. Ethanol intake was measured on postnatal days 42-68. Anxiety-like behavior and exploratory responses were assessed using the light-dark box and multivariate concentric square field test. Results: Environmental enrichment increased ethanol intake in female, but not male, ADHI2 and ADLO2 rats (p < 0.05) and increased risk-taking and exploratory behavior (p < 0.05). Before environmental enrichment or ethanol exposure, ADHI2 rats exhibited reduced risk-taking and increased anxiety-like behavior (p < 0.05). Conclusions: The findings indicate that environmental enrichment increased ethanol intake in female, but not male, rats. Clinical programs that treat alcohol use disorder by emphasizing environmental stimulation should be designed with caution.