237 -- Tetrahydrocannabinol produces locomotor hyperactivity and disrupts circadian rhythmicity in pregnant or nursing Long-Evans rats.

Studies have demonstrated that exposure to cannabis during development impairs cognitive processes in humans, as well as locomotor activity and learning in animals. This extends to pregnant women and those caring for newborns. The legalization of marijuana can confer an underestimation of the effects of the more potent cannabinoids such as tetrahydrocannabinol (THC). This can lead to increased in utero exposure and postnatal exposure via breastfeeding. Newborns can also be affected if maternal care is compromised during an acute high. The current study used VitalView software and cage-top infrared activity monitors to quantify the effects of a range of THC doses on activity and circadian rhythms in pregnant or lactating rats. Our preliminary results found that control animals maintain relatively similar activity levels prior to and after dosing. THC-dosed animals show increased activity after dosing. The increased activity comes at the expense of nesting and maternal care behaviors. Applying the findings of this study clinically will serve a future goal of properly educating the public to prevent the detrimental effects of marijuana use on children.