The effects of increasing endocannabinoids on repetitive behavior in a mouse model of autism spectrum disorder

The endocannabinoid system is a neuromodulatory system with broad effects throughout the brain, including areas that regulate behaviors related to autism. The endocannabinoid system has been reported to be under stimulated in autism. These experiments utilize a mouse model of autism, the BTBR T+ Itpr3tf/J (BTBR) inbred of strain of mice that have high levels of repetitive behaviors. These mice were administered drugs that block the degradation of the two major endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG); and tested for repetitive behaviors. Repetitive behaviors were examined using marble burying, spontaneous grooming, and water T-maze reversal tests. The results suggest sex-specific effects on repetitive behaviors, where male mice had reduced repetitive behavior when 2-AG was increased and females when anandamide was increased in the marble burying and spontaneous grooming tests. Neither drug affected water T-maze reversal learning. These data suggest that repetitive behaviors with lower cognitive load are affected by the endocannabinoid system.