Аннотация:Dopamine is thought to regulate learning from reward and punishment.It has been proposed that dopamine neurons signal value prediction error (VPE), the difference between the values of actual and predicted outcomes.However, how dopamine neurons integrate information about aversive events remains controversial.Some studies have shown that aversive stimuli inhibit dopamine neurons, while others have suggested that aversive events activate some dopamine neurons.One recent study postulated that dopamine neurons ignore aversive events.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 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 uncover different modes of dopamine signaling, each of which may be adaptive for different environments.
