Abstract
Associative learning provides a mean to learn appropriate valence and salience value signals that animal can later use to make appropriate value-based choices. By generalizing from prior aversive experience and comparing motivational salience signals to a current one, animals can learn the relative aversive (better or worse than) value or relative positive safety between experiences. Yet, how such relative value signals are acquired during learning remain poorly known. The paraventricular nucleus of the thalamus (PVT) is critical for the control of salience and valence signals, therefore it is well-placed to be involved in learning relative aversive value and learned safety. Using a newly-developed conditioned place aversive task, we first uncover specific behavioral signatures associated with learning relative aversive value and learned safety, and related value-based choices. We then show that neurons expressing dopamine D2 receptor (D2+) in the anterior PVT (aPVT) rather than posterior PVT (pPVT), are preferentially recruited by both relative aversive value learning and learned safety. By employing a chemogenetic inactivation strategy, we first demonstrate a role of aPVT D2+ neurons for learning relative aversive value by regulating motivational aversive salience. Finally, we show that the same chemogenetic intervention also increases learned safety salience. Overall, our data are the first to demonstrate that aPVT D2+ neurons modulate the salience of experience independently of valence to compute adapted learned value signals during learning and promote appropriate value-based choices.