Learning and memory impairment induced by salvinorin A, the principal ingredient of Salvia divinorum, in wistar rats.
The effects of salvinorin A (Salvia divinorum principal ingredient), a potent κ-opioid natural hallucinogen, on learning and memory were investigated. Wistar rats were tested in the 8-arm radial maze, for object recognition and passive avoidance tasks for spatial, episodic, and aversive memory. Attention was assessed using a latent inhibition task. Salvinorin A (80-640 μgkg subcutaneous sc) did not affect short-term memory, but it impaired spatial long-term memory. Episodic and aversive memories were impaired by salvinorin A (160-640 μgkg). Memory impairment was blocked by the selective κ-opioid receptor antagonist, nor-binaltorphimine (nor-B 0.5-1 mgkg, intraperitoneal ip). Salvinorin A (160 μgkg) disrupted latent inhibition, after LiCl treatment, such as reduced sucrose intake, suggesting an attention would result in an impairment of cognitive behavior. These findings demonstrate for the first time that salvinorin A has deleterious effects on learning and memory, through a κ-opioid receptor mechanism.