GEPTAKHOR
Experiment 1996 DOI: 10.1163/2211730x96x00153 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental animal study Peer reviewed |
|---|---|
| Population | Rats |
| Intervention | MDMA |
| Dose | 20 mg/kg s.c., twice daily for 4 days |
| Duration | Two weeks after MDMA administration |
| Citations | 42 |
| Key findings | Two weeks after a neurotoxic MDMA regimen in rats, serotonin neuron density and firing in the dorsal raphe nucleus and baseline extracellular serotonin in the frontal cortex and hippocampus were unchanged, while 5-HIAA was reduced by about 50% in both regions. Stimulated serotonin release was preserved in the hippocampus but markedly reduced in the frontal cortex, suggesting serotonin function is maintained in some, but not all, forebrain regions despite neurotoxicity. |
Abstract
In experimental animals, administration of 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) leads to extensive, but incomplete, loss of 5-hydroxytryptamine (5-HT) innervation in the brain. Here, we report the effects of MDMA on 5-HT neuronal function measured in the rat in vivo using electrophysiological and microdialysis techniques. Two weeks after administration of an established neurotoxic regimen of MDMA (20 mg/kg s.c., twice daily for 4 days) we found; 1) no change in either the density or the firing activity of 5-HT neurons in the dorsal raphé nucleus; 2) no change in basal extracellular 5-HT in either the frontal cortex or the hippocampus, although extracellular 5-hydroxyindoleacetic acid was reduced by about 50% in both regions; and 3) no change in the amount of 5-HT released in the hippocampus in response to electrical stimulation (5 Hz) of either the dorsal or medial raphé nucleus, but a marked reduction in the amount of 5-HT released in the frontal cortex after electrical stimulation of the dorsal raphé nucleus. In summary, although MDMA causes marked 5-HT neurotoxicity, our data suggest that 5-HT cell firing is unchanged and, furthermore, that 5-HT release is maintained in some (but not all) forebrain regions even in response to physiological levels of stimulation.