Drug-drug discrimination: stimulus properties of drugs of abuse upon a serotonergic-dopaminergic continuum.
Pharmacology, biochemistry, and behavior January 1997 DOI: 10.1016/s0091-3057(96)00161-x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study (drug discrimination paradigm) Peer reviewed |
|---|---|
| Sample size | 10 |
| Population | Male N/Nih rats |
| Interventions | d-amphetamine norfenfluramine LSD MDMA methcathinone 7-OH-DPAT |
| Dose | d-amphetamine 0.4 mg/kg; norfenfluramine 0.7 mg/kg; other drugs not specified |
| Topics | Serotonin |
| Key findings | LSD and MDMA generalized to the norfenfluramine-appropriate lever in a dose-responsive manner, while methcathinone and 7-OH-DPAT generalized to the amphetamine-appropriate lever. Simultaneous administration of both training drugs produced random responding, indicating equivalent cueing strength. |
Abstract
Ten male N/Nih rats were trained to discriminate between the interoceptive cues produced by the purportedly dopaminergically-mediated drug d-amphetamine at 0.4 mg/kg intraperitoneally administered 20 min prior to training and those produced by the purportedly serotonergically-active agent norfenfluramine at 0.7 mg/kg. Once this discrimination was successfully acquired, the rats were tested with saline and with both drugs administered simultaneously and these manipulations were seen to produce random responding; indicating roughly equivalent cueing strength. Subsequently, various drugs thought to act upon serotonergic neurons, i.e., LSD and MDMA, were tested and shown to generalize in a dose-responsive manner to the norfenfluramine-appropriate lever. In contrast, the dopaminergically-active agent methcathinone and the D3 agonist 7-OH-DPAT produced generalization on the amphetamine-appropriate lever. Results are discussed in light of the increased specificity of behavioral testing available in a drug vs. drug discriminative paradigm using two drugs with different mechanisms of action.