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Effects of Repeated Administration of 3,4-methylenedioxymethamphetamine (MDMA) on Avoidance Memory and Cell Density
Mehrdad Jahanshahi1, Kamran Haidari1, Simin Mahaki-Zadeh1
1Neuroscience Research Center, Department of Anatomy, Golestan University of Medical Sciences, Gorgan, Iran.
Introduction:
MDMA or ecstasy is a derivative of amphetamines used mostly by young people worldwide. Although the acute effects of this drug are known, the effect of chronic administration is not well studied. Therefor the aim of this study was to determine the effects of repeated (long term) administration of MDMA on rats' memory and their hippocampal cell density.
Method:
Young adult male Wistar rats 200 ± 20 g served as subjects. The rats were randomly distributed into three MDMA treated groups (3×2.5 mg/kg, 3×5 mg/kg, 3×10 mg/kg) and one control-saline group. All animals received MDMA intraperitoneally (3h apart; a challenge) 7th day of every week for consecutive 4 weeks. Animals were trained before and were tested after injections for their memory status using the standards passive avoidance method. Finally, 24hr after the memory test, rats were sacrificed and after tissue operations, the hippocampal astrocytes and neurons were counted.
Results:
Results showed that the number of neurons in all experimental groups was lower than the control-saline group. The most decreased number of neurons was shown in 5 mg/kg MDMA group compared to control-saline in all the regions of hippocampus. Also we found that repeated administration of MDMA reduced the number of hippocampal astrocytes.
Discussion:
It is concluded that repeated administration of MDMA can reduce density of neurons and astrocytes and this decrease is not dose dependence.
Insights
Repeated MDMA use in rats significantly reduced hippocampal neuron and astrocyte density, impacting memory. This neurotoxic effect was observed across various doses, indicating potential long-term risks associated with ecstasy consumption.
Area of Science:
- Neuroscience
- Pharmacology
- Toxicology
Background:
- MDMA (3,4-methylenedioxymethamphetamine), commonly known as ecstasy, is a widely used recreational amphetamine derivative.
- While acute MDMA effects are documented, the consequences of chronic administration remain less understood.
- This study investigates the long-term impact of MDMA on cognitive function and brain structure.
Purpose of the Study:
- To evaluate the effects of repeated MDMA administration on memory in rats.
- To determine the impact of chronic MDMA exposure on hippocampal cell density, specifically neurons and astrocytes.
Main Methods:
- Young adult male Wistar rats were administered varying doses of MDMA (2.5, 5, 10 mg/kg) or saline intraperitoneally weekly for four weeks.
- Memory function was assessed using the passive avoidance method before and after the treatment period.
- Following the memory tests, hippocampal tissues were analyzed to count neuron and astrocyte populations.
Main Results:
- Chronic MDMA administration led to a significant decrease in hippocampal neuron density across all experimental groups compared to controls.
- The most pronounced reduction in neuron numbers was observed in the 5 mg/kg MDMA group.
- Repeated MDMA exposure also resulted in a decreased number of hippocampal astrocytes, irrespective of the dose.
Conclusions:
- Repeated MDMA administration negatively affects hippocampal cell density, reducing both neuron and astrocyte numbers.
- The observed decrease in hippocampal cell density is not strictly dose-dependent.
- These findings suggest potential neurotoxic effects of long-term MDMA use on brain structure and cognitive function.
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