Differences in the stimulus properties of 3,4-methylenedioxyamphetamine and 3,4- methylenedioxymethamphetamine in animals trained to discriminate hallucinogens from saline.
The stimulus properties of 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) and several related compounds were compared to those of (+)-lysergic acid diethylamide (LSD) and mescaline (3,4,5-trimethoxyphenylethylamine) in a two-lever, water-reinforced, drug discrimination task. In animals trained to discriminate LSD (0.08 mg/kg) from saline (n = 8), LSD-like responding occurred during substitution (generalization) tests with sufficiently high doses of (+/- )-2,5-dimethoxy-4-methylamphetamine, LSD, mescaline, psilocybin and (-)-MDA; saline appropriate responding occurred after (+)-MDA and both (+)- and (+)- and (-)-MDMA. In animals trained to discriminate mescaline (10 mg/kg; n = 8), (-)-MDA, (+)-MDA, (-)-MDMA and (+)-MDMA as well as (+/- )-2,5-dimethoxy-4-methylamphetamine, LSD, mescaline and psilocybin mimicked the training drug. Neither (+)-amphetamine nor cocaine produced mescaline-like responding; fenfluramine substituted partially for mescaline but not LSD. Because all of the phenylisopropylamine enantiomers mimicked the potent hallucinogen mescaline (10 mg/kg), these results do not support suggestions that similarities in the behavioral effects of "designer" drugs such as MDA and MDMA to those of hallucinogens are limited to (-)-MDA. They also indicate that, although LSD and mescaline may be pharmacologically similar (in other assays), these compounds do not have identical stimulus properties.
D015104:3,4-Methylenedioxyamphetamine / Q000031:analogs & derivatives / Q000494:pharmacology*; D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006213:Hallucinogens; D008238:Lysergic Acid Diethylamide; D008297:Male; D008635:Mescaline; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D051381:Rats; D011919:Rats, Inbred Strains
D000662:Amphetamines; D006213:Hallucinogens; D015104:3,4-Methylenedioxyamphetamine; D008238:Lysergic Acid Diethylamide; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D008635:Mescaline