Increasing the selectivity of drug discrimination procedures.
J B Appel, W B West, W G Rolandi, T Alici, K Pechersky
Pharmacology, biochemistry, and behavior October 1999 DOI: 10.1016/s0091-3057(99)00089-1 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Animal experiment Peer reviewed |
|---|---|
| Population | Rats |
| Interventions | LSD Cocaine Pentobarbital DMT DOM MDMA PCP Lisuride Quipazine Yohimbine |
| Dose | LSD 0.08 mg/kg, cocaine 10 mg/kg, pentobarbital 5 mg/kg; substitution test doses not fully specified (ED50s given for lisuride 0.012, quipazine 1.662, yohimbine 2.344, MDMA 1.38) |
| Duration | 31 days for LSD-other acquisition, 26 days for LSD-saline acquisition |
| Key findings | The LSD-other discrimination procedure was more selective than the standard LSD-saline procedure: lisuride, quipazine, and yohimbine substituted for LSD in LSD-saline-trained rats but not in LSD-other-trained rats, while hallucinogens substituted in both groups. |
Abstract
In an attempt to increase the selectivity of drug discrimination, rats were trained to discriminate LSD (0.08 mg/kg) from a group of "other" compounds consisting of cocaine (10 mg/kg), pentobarbital (5 mg/kg), and saline. Acquisition of this LSD-other discrimination was rapid (31 days) in chambers equipped with retractable levers and did not differ significantly from that of a group of animals trained to discriminate LSD from saline (26 days). In substitution (generalization) tests, hallucinogens such as LSD, DMT, and DOM mimicked LSD in a dose-dependent manner in both groups. The designer drug (+/-)MDMA substituted for LSD in the LSD-other group (ED50 = 1.38) but did not substitute for the training drug in the LSD-ND group; neither (+) MDMA nor PCP mimicked LSD in either group. Most importantly, lisuride, quipazine, and yohimbine, drugs that have been described as "false positives," substituted for LSD in animals trained to discriminate LSD from saline (ED50s = 0.012, 1.662, 2.344, respectively), but not in animals trained to discriminate LSD from other drugs. Thus, the LSD-other training procedure can be described as more selective than the standard drug-ND procedure.