Striatal dopamine (DA) release has long been linked to reward processing, but it remains controversial whether DA release reflects costs or benefits, and how these signals vary with motivation. Here we measure DA release in the nucleus accumbens and dorsolateral striatum while independently varying costs and benefits, and apply behavioural economic principles to determine an animal’s level of motivation. We reveal that DA release in both structures incorporates both reward magnitude and sunk cost. Surprisingly, motivation was inversely correlated with reward-evoked DA release; the higher the motivation for rewards the lower the reward-evoked DA release. Our results reconcile previous disparate findings by demonstrating that striatal DA release simultaneously encodes cost, benefit and motivation but in distinct manners over different time scales.  


Neir Eshel joined the faculty at Stanford University in 2021 as an assistant professor in the Department of Psychiatry & Behavioural Sciences. He received his A.B. from Princeton University, M.Sc. from University College London, and M.D./Ph.D. from Harvard University. For his Ph.D. work with Naoshige Uchida, he used optogenetics, electrophysiology and behavioural approaches to probe the neural circuit regulating dopamine release as mice learned about rewards. He then completed psychiatry residency at Stanford University, where he extended his interest in dopamine to study the role of this circuit in clinically relevant behaviours, including aggression and addiction. In addition to running a small lab (www.staarlab.com), Neir also maintains a clinical practice and hopes to translate his basic neuroscience findings into new treatment options for his patients.