3,4-Methylenedioxymethamphetamine-induced release of serotonin and inhibition of dorsal raphe cell firing: potentiation by L-tryptophan
Sprouse JS, Bradberry CW, Roth RH, Aghajanian GK.
Department of Psychiatry,
Yale University School of Medicine,
New Haven, CT 06508.
Eur J Pharmacol 1990 Mar 27;178(3):313-20


The effects of the serotonin (5-HT) precursor L-tryptophan on MDMA (3,4-methylenedioxymethamphetamine)-induced inhibition of dorsal raphe neuronal firing were characterized using extracellular single-unit recording and microdialysis techniques in the in vitro midbrain slice preparation. Pretreatment with L-tryptophan (100 microM) lowered the doses of MDMA required to inhibit unit activity. Based upon IC50 values, L-tryptophan increased the potency of MDMA by approximately 3-fold. In a parallel series of experiments, microdialysis probes resting on the brain slice surface provided a means to estimate 5-HT release from the dorsal raphe nucleus. Pretreatment with L-tryptophan increased MDMA-induced 5-HT release in a manner consistent with the suppression of dorsal raphe cell firing: compared to untreated preparations, peak 5-HT release, total release and the duration of release were all increased. Taken together, these data suggest that the enhancement by L-tryptophan of MDMA-induced 5-HT release and inhibition of dorsal raphe neuronal firing is due to an increase in the amount of 5-HT available for release. The question is raised as to what effect L-tryptophan may have on the psychotropic and neurotoxic actions of MDMA.

Protect and survive
MDMA and immunity
Ecstasy and serotonin synthesis
Ecstasy and tryptophan hydroxylase
Memory, tryptophan supplementation and MDMA use

and further reading

Future Opioids
BLTC Research
Utopian Surgery?
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
Critique of Huxley's Brave New World

The Good Drug Guide
The Good Drug Guide

The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family