278 -- Tetrahydrocannabinol Compromises Maternal Nest Maintenance and Nursing Behaviors in the Long-Evans Rat

The legalization of marijuana for recreational use in New York State implies that it is a safe drug that has been thoroughly screened for developmental and neurotoxic effects. The current study examined the hypothesis that the most potent cannabinoid, tetrahydrocannabinol (THC), could negatively affect neonatal development by compromising maternal care. To examine this, female rats were administered 0, 1.25, 2, 5, or 10mg/kg THC while caring for their newborn litters. A surveillance camera was used to record their behaviors in the home cage, 24/7, from birth through postnatal day 5. Our preliminary analysis focused on the behaviors performed 1 hour prior to and 2 hours following the daily THC dose. We found evidence of maladaptive self-directed maternal behaviors such as stereotypical tail-chasing as well as maladaptive pup-directed behaviors. Pups were scattered throughout the cage and buried in cage bedding rather than gathered in a nest. In some cases, neglect was severe, leading to litter attrition. These data suggest that even low doses of THC can disrupt the interactions between a maternal caregiver and her newborn, during a period that is critical for brain and social development.