Given that human adolescents usually consume ethanol (EtOH) in the presence of high noise intensities, the use of an animal model could provide relevant data. Therefore, the aim of the present study was to assess whether both agents could produce changes in different behavioral parameters in adolescent rats.
Male Wistar rats in early adolescence (28 days old) were subjected to voluntary EtOH consumption for intermittent 24-hour periods for two weeks, using the two-bottle choice paradigm (5% EtOH/1% sucrose). A subgroup was exposed to noise (2h, 95-97 dB) after the first week. All animals were evaluated on different behavioral tasks, including open field, elevated plus maze and inhibitory avoidance.
Results showed a decrease in associative memory (AM) and an increase in anxiety-like behaviors after noise exposure or EtOH intake, when compared with sham rats. In noise-exposed animals that consumed EtOH, an increase in exploratory behavior was also observed.
This findings suggest that exposure to stressors such as noise or EtOH presented individually might trigger an increase in anxiety-like behaviors that seem to lead to a deficit in AM. A counteraction of anxiety-related behaviors seems to be added when both agents are present together, suggesting a compensation of the stressful effect.
In conclusion, adolescence would represent a period of great vulnerability to physical and chemical agents that may interact to achieve more adaptive behavioral performance.