Erowid.org: Erowid Reference 284 : The relationship between the degree of neurodegeneration of rat brain 5-HT nerve terminals and the dose and frequency of administration of MDMA ('ecstasy') : O'Shea E, Granados R, Esteban B, Colado MI, Green AR

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O'Shea E, Granados R, Esteban B, Colado MI, Green AR.

“The relationship between the degree of neurodegeneration of rat brain 5-HT nerve terminals and the dose and frequency of administration of MDMA ('ecstasy')”.

Neuropharmacology. 1998;37(7):919-26.

Abstract

The effect of varying the dose and frequency of administration of 3,4-methylenedioxymethamphetamine (MDMA or ‘ecstasy’) on both the acute hyperthermic response and the long term neurodegeneration of 5-hydroxytryptamine (5-HT) nerve terminals in the brain has been studied in Dark Agouti rats. A single injection (4–15 mg:kg i.p.) of MDMA produced immediate dose-related hyperthermia and a dose-related decrease in 5-HT, 5-hydroxyindoleacetic acid (5-HIAA) and [3H] paroxetine binding in regions of the brain 7 days later, with a dose of 4 mg:kg having no degenerative effect. This dose was also without effect when given once daily for 4 days, but produced a marked loss of [3H] paroxetine binding and indole concentration ( ~55%) when given twice daily for 4 days. When a dose of 4 mg:kg was given twice weekly for 8 weeks it had no effect on these serotoninergic markers, despite a clear anorectic effect of the drug being seen. These data demonstrate that MDMA-induced neurodegeneration is related to both the dose and frequency of administration and indicate that damage to 5-HT neurones can occur in the absence of a hyperthermic response to the drug. We suggest that damage occurs when endogenous free radical scavenging mechanisms become overwhelmed or exhausted.