Serotonin type 5A receptor antagonists inhibit D-lysergic acid diethylamide discriminatory cue in rats.
Like other psychedelics, D-lysergic acid diethylamide (LSD) affects numerous serotonin receptors, and according to the current dogma, the 5-HT Using male Sprague Dawley rats, we examined the effects of 5-HT In animals trained to discriminate 0.08 mgkg LSD from vehicle 15 minutes after injection, LSD produced dose-related increases in response, with an ED50 (±95% confidence limits) of 0.0384 (± 0.025-0.051) mgkg). LSD-like responses were observed when the training dose of LSD was given 5-30 but not 90 minutes before the test. Confirming earlier reports, the 5-HT antagonist ketanserin (2 mgkg) attenuated the LSD response in 50% of rats, and due to pretreatment with 0.2 and 2 mgkg MDL 100907, 63% and 67% of animals, respectively, failed to select the LSD lever. We then investigated the effects of two 5-HT The present results suggest that antagonists of the 5-HT