Mesolimbic dopamine signals the value of work.

Autor: Hamid AA; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA.; Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA., Pettibone JR; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA., Mabrouk OS; Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.; Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA., Hetrick VL; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA., Schmidt R; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA., Vander Weele CM; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA., Kennedy RT; Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.; Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA., Aragona BJ; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA.; Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA., Berke JD; Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA.; Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA.; Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.
Jazyk: angličtina
Zdroj: Nature neuroscience [Nat Neurosci] 2016 Jan; Vol. 19 (1), pp. 117-26. Date of Electronic Publication: 2015 Nov 23.
DOI: 10.1038/nn.4173
Abstrakt: Dopamine cell firing can encode errors in reward prediction, providing a learning signal to guide future behavior. Yet dopamine is also a key modulator of motivation, invigorating current behavior. Existing theories propose that fast (phasic) dopamine fluctuations support learning, whereas much slower (tonic) dopamine changes are involved in motivation. We examined dopamine release in the nucleus accumbens across multiple time scales, using complementary microdialysis and voltammetric methods during adaptive decision-making. We found that minute-by-minute dopamine levels covaried with reward rate and motivational vigor. Second-by-second dopamine release encoded an estimate of temporally discounted future reward (a value function). Changing dopamine immediately altered willingness to work and reinforced preceding action choices by encoding temporal-difference reward prediction errors. Our results indicate that dopamine conveys a single, rapidly evolving decision variable, the available reward for investment of effort, which is employed for both learning and motivational functions.
Databáze: MEDLINE
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