Presynaptic dopamine function measured with [18F]fluorodopa and L-DOPA effects on impulsive choice

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Contributors

Abstract

We previously reported that L-DOPA effects on reward-based decision-making in a randomized, placebo-controlled, double-blind, crossover study were consistent with an inverted U-shaped function whereby both low and high extremes of dopamine signaling are associated with high-impulsive choice. To test this hypothesis, we performed [18F]DOPA positron emission tomography in 60 of the 87 participants in that study, and measured the effective distribution volume ratio (EDVR) of [18F]DOPA influx rate to [18F]dopamine washout rate, an index of presynaptic dopaminergic function. Participants with higher baseline EDVR self-reported lower impulsivity, and discounted rewards as a function of delay more strongly after receiving L-DOPA, whereas the opposite was detected for those with lower baseline EDVR. Our findings support a relationship of striatal dopaminergic activity to trait impulsivity, and the view that there is a non-linear, possibly inverted U-shaped relationship of striatal dopaminergic function with delay discounting. Individuals with optimal dopamine signaling would become more impulsive when receiving dopamine-enhancing drugs, whereas those with suboptimal dopaminergic signaling would benefit and exhibit less impulsive choice. Consideration of differences in endogenous dopamine signaling and possibly also other neurotransmitter activity may be crucial to advance understanding of the neurobiochemical mechanisms of impulsive decision-making and related mental disorders.

Details

Original languageEnglish
Article number17927
JournalScientific reports
Volume9
Issue number1
Publication statusPublished - 1 Dec 2019
Peer-reviewedYes

External IDs

PubMed 31784559
ORCID /0000-0003-4163-9014/work/143783439
ORCID /0000-0001-5398-5569/work/150329499

Keywords

ASJC Scopus subject areas