Psychopharmacology
January 1, 1987
Kathryn A. Cunningham, J. B. Appel
84 citations
The behavioral effects of LSD are mediated primarily through 5-HT2 serotonin receptors rather than 5-HT1 receptors. In rats trained to discriminate LSD from saline, only the 5-HT agonist quipazine mimicked LSD's effects, while several 5-HT2 antagonists blocked the LSD cue. Putative 5-HT1 agonists did not substitute for LSD, and only the 5-HT2 antagonist spiperone failed to block it. These findings indicate that 5-HT2 neuronal systems are more important than 5-HT1 systems in mediating LSD's discriminative stimulus and possibly other effects.
Behavioural Pharmacology
April 1, 1995
Lisa E. Baker, Jonathan M. Broadbent, E. K. Michael et al.
52 citations
In rats trained to distinguish either the (+)- or (-)-isomer of MDMA from saline, both isomers of MDMA and MDA fully substituted for the training drugs. Stimulants like amphetamine and cocaine did not substitute. Hallucinogens such as DOM, LSD, and mescaline did not fully substitute for (+)-MDMA; LSD substituted for (-)-MDMA only at a specific dose. The serotonin-releasing agents fenfluramine and p-chloroamphetamine substituted partially or fully for both isomers. Serotonin receptor antagonists pirenpirone and metergoline did not consistently block MDMA's effects. The findings suggest that serotonin release, but not action at 5-HT(2) receptors, is important for the discriminative stimulus effects of MDMA isomers.
Behavioural Pharmacology
October 1, 1992
Jonathan M. Broadbent, J. B. Appel, E. K. Michael et al.
18 citations
In rats trained to distinguish either the left- or right-handed form (isomer) of the drug MDA from saline, both isomers served as reliable cues at specific doses. The two isomers substituted for each other, and both were fully substituted by the related drug MDMA. The hallucinogens LSD and DOM substituted only for the left-handed isomer, while stimulants like amphetamine and cocaine did not produce MDA-like effects. The left-handed isomer's cue was blocked by a serotonin receptor antagonist, but dopamine blockers had no effect. Neither MDA isomer fully substituted for LSD or amphetamine cues, suggesting the left-handed isomer has more hallucinogen-like and serotonin-mediated effects, while both lack strong amphetamine-like properties.