TY - JOUR T1 - A Transient Dopamine Signal Represents Avoidance Value and Causally Influences the Demand to Avoid JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0058-18.2018 SP - ENEURO.0058-18.2018 AU - Katherine J. Pultorak AU - Scott A. Schelp AU - Dominic P. Isaacs AU - Gregory Krzystyniak AU - Erik B. Oleson Y1 - 2018/04/10 UR - http://www.eneuro.org/content/early/2018/04/10/ENEURO.0058-18.2018.abstract N2 - While an extensive literature supports the notion that mesocorticolimbic dopamine plays a role in negative reinforcement, recent evidence suggests that dopamine exclusively encodes the value of positive reinforcement. In the present study, we employed a behavioral economics approach to investigate whether dopamine plays a role in the valuation of negative reinforcement. Using rats as subjects, we first applied fast-scan cyclic voltammetry to determine that dopamine concentration decreases with the number of lever presses required to avoid electrical footshock (i.e. the economic price of avoidance). Analysis of the rate of decay of avoidance demand curves, which depict an inverse relationship between avoidance and increasing price, allows for inference of the worth an animal places on avoidance outcomes. Rapidly decaying demand curves indicate increased price sensitivity, or low worth placed on avoidance outcomes, while slow rates of decay indicate reduced price sensitivity, or greater worth placed on avoidance outcomes. We therefore used optogenetics to assess how inducing dopamine release causally modifies the demand to avoid electrical footshock in an economic setting. Increasing release at an avoidance predictive cue made animals more sensitive to price, consistent with a negative reward prediction error (i.e., the animal perceives they received a worse outcome than expected). Increasing release at avoidance made animals less sensitive to price, consistent with a positive reward prediction error (i.e., the animal perceives they received a better outcome than expected). These data demonstrate that transient dopamine release events represent the value of avoidance outcomes and can predictably modify the demand to avoid.Significance Statement Dopamine is thought to play a crucial role in reward learning and directing actions toward beneficial outcomes. While the avoidance of harmful stimuli is similarly pertinent to an organism’s survival, the role of dopamine in avoidance remains controversial. Using in vivo electrochemistry, we observed that dopamine concentration decreased when the effort (lever presses) required to avoid electrical footshock increased. We also found that increasing dopamine at an avoidance predictive cue decreased avoidance, consistent with a negative prediction error. In contrast, increasing release at successful avoidance increased avoidance, consistent with a positive prediction error. These data demonstrate that transient dopamine release events represent the value of avoidance outcomes and capably modify avoidance. ER -