Impact of Enriched Environment on Hippocampal-Related Behavioral Changes Induced by Extended Voluntary Ethanol Intake...

The developing brain is vulnerable to ethanol intake and noise exposure, agents that adolescents are commonly exposed to. The aim of this study was to evaluate whether 2 weeks of ethanol, combined with intermediate noise exposure, can affect different behaviors, using an animal model. In addition, enriched environment housing was used as a neuroprotective strategy. Adolescent Wistar rats of both sexes were subjected to a 6-session voluntary two-bottle choice ethanol paradigm. A subgroup was exposed to noise for 2 h after Session 3, and some rats were housed in enriched cages. Open field, elevated plus maze, and inhibitory avoidance tasks were used to assess hippocampal-related behaviors. Present results show sex- and housing-dependent changes in ethanol intake, showing an overall decrease in consumption, with females increasing preference in the last sessions. Exposure to both agents impaired associative memory in both sexes. In contrast, whereas ethanol had anxiolytic effects in females, together with increased novelty-seeking and exploratory behavior, opposite changes were found in males. Noise exposure increased anxiety-like behavior in both sexes, but males and females displayed opposing alterations in other behavioral measures. Combined exposure resulted in effects equal to or less pronounced than those elicited by noise alone. Most behavioral changes were prevented, at least partially, by enriched environment housing. These findings suggest that this animal model may provide insights into the behavioral alterations observed in adolescents exposed to alcohol and noise in leisure settings. Additionally, an enriched environment proved to be a partially effective neuroprotective strategy in both sexes.