Effects of URB597 as an inhibitor of fatty acid amide hydrolase on WIN55, 212-2-induced learning and memory deficits in rats

Cannabinoid and endocannabinoid systems have been implicated in several physiological functions including modulation of cognition. In this study we evaluated the effects and interaction between fatty-acid amide hydrolase (FAAH) inhibitor URB597 and CB1 receptor agonist WIN55, 212-2 on memory using object recognition and passive avoidance learning (PAL) tests. Learning and memory impairment was induced by WIN 55, 212-2 administration (1 mg/kg, i.p.) 30 min before the acquisition trial. URB597 (0.1, 0.3 and 1 mg/kg, i.p.) or SR141716A (1 mg/kg, i.p.) was injected to rats 10 min before WIN 55, 212-2 or URB597 respectively. URB597 (0.3 and 1 mg/kg) but not 0.1 mg/kg induced higher discrimination index (DI) in object recognition test and enhanced memory acquisition in PAL test. The cognitive enhancing effect of URB597 was blocked by a CB1 receptor antagonist, SR141716A which at this dose alone had no effect on cognition. WIN55, 212-2 caused cognition deficits in both tests. URB597 (0.3 and 1 mg/kg) treatment could alleviate the negative influence of WIN 55, 212-2 on cognition and memory. These results indicate URB597 potential to protect against memory deficits induced by cannabinoid. Therefore, in combination with URB597 beneficial effects, this study suggests that URB597 has recognition and acquisition memory enhancing effects. It may also constitute a novel approach for the treatment of cannabinoid induced memory deficits and lead to a better understanding of the brain mechanisms underlying cognition.