Estrogen improves response accuracy and attenuates the disruptive effects of delta9-THC in ovariectomized rats responding under a multiple schedule of repeated acquisition and performance.

Despite evidence of an interaction between cannabinoids and estrogen in the brain, little information is available regarding the consequences of this interaction on behavior. A within-subjects design was used to examine the effects of estrogen and delta9-tetrahydrocannabinol (delta9-THC) on learning and memory in ovariectomized rats responding under a multiple schedule of repeated acquisition and performance. Treatment with low physiological levels of estrogen, delivered in Silastic capsules, improved response accuracy without affecting response rate during acquisition. Estrogen also attenuated the ability of delta9-THC (0.56- 3.2 mg/kg) to decrease response accuracy and rate during acquisition and response accuracy during performance. Results indicate that estrogen can improve accuracy during acquisition of a nonspatial operant task and can attenuate delta9-THC- induced behavioral deficits.