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Quenten Highgate

Victoria University of Wellington

2 papers in the library · 49 citations · publishing 2019-2021

Papers

Methylenedioxymethamphetamine (MDMA): Serotonergic and dopaminergic mechanisms related to its use and misuse

Journal of Neurochemistry March 12, 2021 Susan Schenk, Quenten Highgate 47 citations

MDMA, an amphetamine analogue, primarily stimulates serotonin release with smaller increases in synaptic dopamine. The ratio of dopamine to serotonin increase predicts abuse liability, with higher ratios indicating greater risk. Despite a lower ratio, MDMA is misused. Repeated exposure produces neuroadaptive changes in both serotonin and dopamine systems, explaining the development and maintenance of self-administration in animals and substance use disorder in humans. Research shows serotonin inhibits the acquisition of MDMA self-administration, while dopamine is critical for its maintenance. The paper describes circuitry and serotonin receptors that modulate dopamine activity and reviews limited research on MDMA's effects on these receptor mechanisms.

DOI: 10.1111/jnc.15348 MDMA Serotonergic Serotonin Amphetamine +10

Dopamine and serotonin antagonists fail to alter the discriminative stimulus properties of ±methylenedioxymethamphetamine

Behavioural Pharmacology June 1, 2019 Susan Schenk, Quenten Highgate 2 citations

Rats trained to recognize a high dose (3.0 mg/kg) of MDMA or amphetamine (0.5 mg/kg) were given drugs that block dopamine or serotonin receptors. Dopamine blockers reduced the rats' ability to recognize amphetamine but not MDMA. Serotonin blockers had no effect on either drug's recognition. The findings suggest that the high-dose MDMA stimulus involves both dopamine and serotonin systems, and either system alone is enough to maintain the drug's effects.

DOI: 10.1097/fbp.0000000000000442