Midbrain dopamine neurons signal aversion in a reward-context-dependent manner


May 11, 2016 - 1:00pm
Northwest 243
About the Speaker
Hideyuki Matsumoto (Uchida Lab)

Dopamine is thought to be a key regulator of learning from appetitive and aversive events. However, whether and how dopamine neurons signal aversion remains controversial. Here we examined how dopamine neurons in the ventral tegmental area respond to aversive events in various conditions. In low reward contexts, most dopamine neurons were exclusively inhibited by aversive events, and their responses to reward and punishment were reduced by expectation. When a single odor predicted both reward and punishment, dopamine neurons’ responses to that odor reflected the integrated value of both outcomes. Thus, dopamine neurons signal value prediction errors (VPEs) integrating information about both reward and aversion in a common currency. In contrast, in high reward contexts, dopamine neurons acquired a short-latency excitation to aversive events that masked their VPE signaling. These results reconcile recent controversies in the field and uncover different modes of dopamine signaling, each of which may be adaptive for different environments.