PT  - JOURNAL ARTICLE
AU  - Jaime J. Castrellon
AU  - Jacob S. Young
AU  - Linh C. Dang
AU  - Ronald L. Cowan
AU  - David H. Zald
AU  - Gregory R. Samanez-Larkin
TI  - Mesolimbic dopamine D2 receptors and neural representations of subjective value
AID  - 10.1101/718858
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 718858
4099  - http://biorxiv.org/content/early/2019/08/01/718858.short
4100  - http://biorxiv.org/content/early/2019/08/01/718858.full
AB  - The process by which the value of delayed rewards is discounted varies from person to person. It has been suggested that these individual differences in subjective valuation of delayed rewards are supported by mesolimbic dopamine D2-like receptors (D2Rs) in the ventral striatum. However, no study to date has documented an association between direct measures of dopamine receptors and neural representations of subjective value in humans. Here, we examined whether individual differences in D2R availability were related to neural subjective value signals during decision making. Human participants completed a monetary delay discounting task during an fMRI scan and on a separate visit completed a PET scan with the high affinity D2R tracer [18F]fallypride. Region-of-interest analyses revealed that D2R availability in the ventral striatum was positively correlated with subjective value-related activity in the ventromedial prefrontal cortex and midbrain but not with choice behavior. Whole-brain analyses revealed a positive correlation between ventral striatum D2R availability and subjective value-related activity in the left inferior frontal gyrus. These findings are the first to identify a link between directly-measured mesolimbic dopamine function and subjective value representation in humans and suggest a mechanism by which individuals vary in neural representation of discounted subjective value.