Locomotor sensitization in male Sprague-Dawley rats following repeated concurrent treatment with 4-methylmethcathinone and 3,4-methylenedioxymethamphetamine
Trent A. Bullock, Michael D. Berquist, Lisa E Baker
Behavioural Pharmacology October 1, 2019 DOI: 10.1097/fbp.0000000000000491 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical experimental study (locomotor sensitization paradigm) Peer reviewed |
|---|---|
| Population | Male Sprague-Dawley rats |
| Interventions | 4-methylmethcathinone (4-MMC) 3 4-methylenedioxymethamphetamine (MDMA) saline |
| Dose | 4-MMC 1.0 mg/kg or 5.0 mg/kg; MDMA 3.0 mg/kg; 4-MMC (1.0 or 5.0 mg/kg) + MDMA (3.0 mg/kg); challenge: saline, 4-MMC 1.0 or 5.0 mg/kg, or MDMA 3.0 mg/kg |
| Duration | 7 consecutive days of daily injections, followed by a 10-day drug-free period and a challenge injection on day 17 |
| Topics | MDMA |
| Key findings | 4-MMC alone (1.0 or 5.0 mg/kg) failed to induce locomotor sensitization, but combined with MDMA (3.0 mg/kg) it induced sensitization to a greater extent than MDMA alone. After 10 days of abstinence, sensitization to a challenge dose of MDMA was expressed only in rats previously exposed to MDMA or to the 5.0 mg/kg 4-MMC + MDMA mixture. The authors argue further research into the abuse liability of 4-MMC/MDMA mixtures may be warranted. |
Abstract
Recreational abuse of illicit synthetic cathinones is an ongoing public health concern. Recent studies indicate that the methcathinone derivative 4-methylmethcathinone (4-MMC) produces behavioral and neurochemical effects similar to the entactogen 3,4-methylenedioxymethamphetamine (MDMA). Whereas polysubstance abuse is common, most preclinical studies of drug abuse liability only evaluate the effects of single drugs. Utilizing the locomotor sensitization paradigm, the present study assessed the combined locomotor stimulant effects of 4-MMC and MDMA for induction of sensitization following repeated administration and for expression of sensitization to a challenge dose of either substance alone after a 10-day period of drug abstinence. Male Sprague-Dawley rats received once daily intraperitoneal injections of saline, 4-MMC (1.0 mg/kg or 5.0 mg/kg), MDMA (3.0 mg/kg), or a mixture containing 4-MMC (1.0 mg/kg or 5.0 mg/kg) + MDMA (3.0 mg/kg) for 7 consecutive days. Following a 10-day drug-free period, rats were given a single intraperitoneal injection of either saline, 4-MMC (1.0 or 5.0 mg/kg), or 3.0 mg/kg MDMA. Activity was recorded for 1 h immediately before and 1 h immediately after injections on days 1, 7, and 17. 4-MMC treatment failed to induce locomotor sensitization, but, when combined with MDMA, sensitization was induced to a greater extent than with MDMA alone. Furthermore, the expression of sensitization to a subsequent challenge dose of MDMA was observed only in animals previously exposed to MDMA or a 5.0 mg/kg 4-MMC + MDMA mixture. In consideration of these findings along with the fact that 4-MMC has similar neurochemical actions to MDMA, further research may be warranted to determine the abuse liability of drug mixtures including 4-MMC and MDMA.
Comparable studies
Other preclinical and animal studies on MDMA, most cited first.
Citations in the library
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