Data from: Mesostriatal dopamine is sensitive to changes in specific cue-reward contingencies

Learning causal relationships relies on understanding how often one event
precedes another. To gain an understanding of how dopamine neuron activity
and neurotransmitter release change when a retrospective relationship is
degraded for a specific pair of events, we used outcome-selective
Pavlovian contingency degradation in rats. Two cues were paired with
distinct food rewards, one of which was also delivered in the absence of
either cue. Conditioned responding was attenuated for the cue-reward
contingency that was degraded. Dopamine neuron activity in the midbrain
and dopamine release in the ventral striatum in response to the cue and
subsequent reward were attenuated during degraded versus non-degraded
trials, and contingency degradation also abolished the trial-by-trial
history dependence of dopamine responses at the time of trial outcome.
This profile of changes in cue- and reward-evoked responding is not easily
explained by a standard reinforcement learning model. An alternative model
based on learning causal relationships was better able to capture evoked
dopamine responses during contingency degradation, as well as conditioned
behavior following optogenetic manipulations of dopamine during
noncontingent rewards. Our results suggest that mesostriatal dopamine
encodes the contingencies between meaningful events during learning.