Nucleus-accumbens dopamine tracks aversive-stimulus duration and prediction but not value or prediction error

The role of dopamine in processing aversive stimuli is under debate: Credits range from no involvement at all, to acting as a punishment-prediction error (PPE) signal. Here, we systematically investigated dopamine release in the nucleus-accumbens core (NAC), which is closely linked to reward-prediction errors, in rats that were exposed to white noise (WN), a versatile, underutilized aversive stimulus, and its predictive cues. Both induced a negative dopamine ramp, followed by slow signal recovery upon stimulus cessation. In contrast to reward conditioning, dopamine was unaffected by WN value, context valence, or probabilistic contingencies, and the WN dopamine-response shifted only partially towards its predictive cue. However, unpredicted WN provoked slower post-stimulus signal recovery than predicted WN. Despite differing signal qualities, dopamine responses to simultaneous presentation of rewarding and aversive stimuli were additive. Together, our findings indicate that instead of a PPE, NAC dopamine primarily tracks prediction and duration of punishment.