Environmental Enrichment Ameliorates Repetitive Behaviors in a Rat Model of Autism

Adverse environmental experiences during early life are identified as potential concerns for neurodevelopmental disorders including autism spectrum disorder (ASD) with 1% prevalence among populations. Maternal separation (MS) is an animal model that is widely used to study long-term behavioral abnormality. To date, a great deal of studies is focused on the potential therapeutic role of environmental enrichment (EE) for the early life stress consequences inducing anxiety, depression, and learning deficits. However, the influence of sex on the effect of environmental enrichment for the autistic-like behaviors induced by maternal separation has not been studied. The focus of the current study is to investigate the therapeutic effect of environmental enrichment on the behavioral deficits related to ASD in female Wistar rats. Pups were separated from the mothers for 3 hours daily from PND1 to PND14. After weaning time (PND21), the rats were subjected to environmental enrichment until behavioral tests day. On PND42-PND50 autism-related behaviors such as social interaction, stereotype behaviors, anxiety behavior, and locomotion were tested. The results showed that EE reduced stereotype behaviors in the maternal separation rat model of autism but increased anxiety behavior (p<0.05). Social behavior and locomotion decreased by maternal separation (p<0.05) but EE had no significant effect on these behavioral abnormalities (p>0.05). The current study demonstrates that repetitive behaviors induced by maternal separation can be treated by EE but anxiety exacerbation may occur which needs more exploration.