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Differences between rats and mice in MDMA (methylenedioxymethylamphetamine) neurotoxicity
B J Logan1, R Laverty, W D Sanderson
1Department of Pharmacology, University of Otago Medical School, Dunedin, New Zealand.
Abstract:
In both rats and mice a single large dose of methylenedioxymethylamphetamine (MDMA; 25 mg/kg i.p.) caused a fall 3 h after injection in the content of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in cortex, a fall in noradrenaline in hippocampus and cerebellum, and a rise in dopamine (DA) but fall in dihydroxyphenylacetic acid (DOPAC) in striatum. These effects were transient, levels being essentially back to normal by 24 h after injection. Repeated large doses (3 x 25 mg/kg in 24 h) of MDMA caused a large long-lasting fall in the content of 5-HT and 5-HIAA in cortex in rats but had only a slight effect in mice. Increasing the dose to 3 x 50 mg/kg in mice produced a large long-lasting fall in striatal DA. The analogue MDEA(3,4-methylenedioxyethylamphetamine) caused a similar slight fall in 5-HT but in contrast to MDMA caused a slight rise in DA content in mice. The nature and degree of neurotoxicity with methylenedioxyamphetamines appears to be drug and species-specific.
Insights
Methylenedioxymethylamphetamine (MDMA) affects neurotransmitters in rats and mice, with effects varying by dose and species. Repeated high doses of MDMA cause long-lasting neurochemical changes, particularly in rats.
Area of Science:
- Neuroscience
- Pharmacology
- Toxicology
Background:
- Methylenedioxymethylamphetamine (MDMA) is a psychoactive drug with known effects on neurotransmitter systems.
- Understanding the neurotoxic potential and species-specific effects of MDMA is crucial for safety and research.
Purpose of the Study:
- To investigate the acute and long-term neurochemical effects of MDMA and its analogue MDEA in rats and mice.
- To determine the dose- and species-dependency of MDMA-induced neurotoxicity.
Main Methods:
- Administration of single and repeated high doses of MDMA and MDEA to rats and mice.
- Measurement of neurotransmitter (5-HT, 5-HIAA, noradrenaline, DA, DOPAC) levels in specific brain regions (cortex, hippocampus, cerebellum, striatum) at different time points post-injection.
Main Results:
- A single high dose of MDMA transiently altered 5-HT, 5-HIAA, noradrenaline, DA, and DOPAC levels in rats and mice.
- Repeated high doses of MDMA induced long-lasting reductions in cortical 5-HT and 5-HIAA in rats, and striatal DA in mice at higher doses.
- MDEA showed different effects on 5-HT and DA compared to MDMA in mice.
Conclusions:
- MDMA-induced neurochemical changes are transient after single high doses but can be long-lasting with repeated high doses.
- The neurotoxic effects of methylenedioxyamphetamines are specific to the drug, dose, and species studied.