Maternal immune activation and adolescent alcohol exposure increases alcohol drinking and disrupts cortical-striatal-hippocampal oscillations in adult offspring
Maternal immune activation (MIA) is strongly associated with an increased risk of developing mental illness in adulthood, which often co-occurs with alcohol misuse. The current study aimed to begin to determine whether MIA, combined with adolescent alcohol exposure (AE), could be used as a model with which we could study the neurobiological mechanisms behind such co-occurring disorders. Pregnant Sprague-Dawley rats were treated with PolyI:C or saline on gestational day 15. Half of the offspring were given continuous access to alcohol during adolescence, leading to four experimental groups: controls, MIA, AE, and Dual (MIA + AE). We then evaluated whether MIA and/or AE alters: 1) alcohol consumption; and 2) cortical-striatal-hippocampal oscillations in adult offspring. Dual rats, particularly females, drank significantly more alcohol in adulthood compared to all other groups. Using machine learning to build predictive models from oscillations, we were able to differentiate Dual rats from control rats and AE rats in both sexes, and Dual rats from MIA rats in females. The current data suggest that MIA+AE (Dual "hits") is a valuable model that we can use to study the neurobiological underpinnings of co-occurring disorders. Our future work aims to extend these findings to other addictive substances to enhance the translational relevance of this model.