Behavioral effects of (+-) 3,4-methylenedioxyamphetamine (MDA) and (+-) 3,4-methylenedioxymethamphetamine (MDMA) in the pigeon: interactions with noradrenergic and serotonergic systems.
M A Nader, S M Hoffmann, J E Barrett
Psychopharmacology 1989 DOI: 10.1007/bf00444689 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Behavioral pharmacology experiment Peer reviewed |
|---|---|
| Population | Pigeons key pecking under a multiple fixed-interval, fixed-ratio schedule of food presentation |
| Interventions | MDA MDMA MDE Metergoline Ketanserin Prazosin |
| Dose | MDA, MDMA, and MDE: 0.1-10.0 mg/kg; Metergoline: 0.1-1.0 mg/kg; Ketanserin: 0.1-3.0 mg/kg; Prazosin: 0.3-3.0 mg/kg |
| Topics | MDMA Serotonin |
| Key findings | MDA, MDMA, and MDE either had no effect or decreased response rates dose-dependently, with MDA at least 1 log unit more potent. Metergoline and ketanserin blocked MDA's rate-decreasing effects but not MDMA's, while prazosin blocked MDMA's effects but not MDA's. The authors conclude that MDA and MDMA, though structurally similar, appear to act through different neurotransmitter systems. |
Abstract
The effects of three amphetamine analogs were assessed in pigeons key pecking under a multiple 3-min fixed-interval (FI), 30 response fixed-ratio (FR) schedule of food presentation. At doses between 0.1 and 10.0 mg/kg, (+-) 3,4-methylenedioxyamphetamine (MDA), (+-) 3,4-methylenedioxymethamphetamine (MDMA), and (+-)-N-ethyl-3,4-methylenedioxyamphetamine (MDE) either had no effect or decreased response rates in both components of the multiple schedule in a dose-dependent manner. MDA was at least 1 log unit more potent than the other two compounds. Metergoline (0.1-1.0 mg/kg), a serotonin (5-HT) antagonist with comparable affinity for the 5-HT1 and 5-HT2 receptor subtypes, blocked the rate-decreasing effects of 3.0 mg/kg MDA in both components of the multiple schedule, but did not affect the MDMA dose-response curve. The 5-HT2 receptor antagonist ketanserin (0.1-3.0 mg/kg) also restored FI and FR responding that was decreased by 3.0 mg/kg MDA, but had no effect on responding suppressed by MDMA. The noradrenergic alpha-1 antagonist prazosin (0.3-3.0 mg/kg) blocked the behavioral effects of 3.0 mg/kg MDMA at doses that did not attenuate MDA's rate-decreasing effects. These results indicate that although MDA and MDMA are structurally similar and have similar behavioral effects, their actions appear to be mediated through different neurotransmitter systems.