In vitro microdialysis: a novel technique for stimulated neurotransmitter release measurements.

A novel microdialysis technique suitable for parallel measurements of neurotransmitter release and single unit recordings from brain slices is presented. The effects of 3,4-methylenedioxymethamphetamine (MDMA) on slices of dorsal raphe nucleus and frontal cortex in a perfusion chamber for electrophysiological measures were studied. MDMA caused measurable release of serotonin which, in the case of the dorsal raphe, was of similar duration as the period of reduced cell firing induced by MDMA. Tryptophan potentiated the action of MDMA. Possible additional applications of this technique are discussed.