A hippocampo-cortical pathway detects changes in the validity of an action as a predictor of reward.

Piquet R(1), Faugère A(1), Parkes SL(2).

Author information:
(1)Univ. Bordeaux, CNRS, INCIA, UMR 5287, 33000 Bordeaux, France.
(2)Univ. Bordeaux, CNRS, INCIA, UMR 5287, 33000 Bordeaux, France. Electronic address: .

Much research has been dedicated to understanding the psychological and neural
bases of goal-directed action, yet the relationship between context and
goal-directed action is not well understood. Here, we used excitotoxic lesions,
chemogenetics, and circuit-specific manipulations to demonstrate the role of the
ventral hippocampus (vHPC) in contextual learning that supports sensitivity to
action-outcome contingencies, a hallmark of goal-directed action. We found that
chemogenetic inhibition of the ventral, but not dorsal, hippocampus attenuated
sensitivity to instrumental contingency degradation. We then tested the
hypothesis that this deficit was due to an inability to discern the relative
validity of the action compared with the context as a predictor of reward. Using
latent inhibition and Pavlovian context conditioning, we confirm that
degradation of action-outcome contingencies relies on intact context-outcome
learning and show that this learning is dependent on vHPC. Finally, we show that
chemogenetic inhibition of vHPC terminals in the medial prefrontal cortex also
impairs both instrumental contingency degradation and context-outcome learning.
These results implicate a hippocampo-cortical pathway in adapting to changes in
instrumental contingencies and indicate that the psychological basis of this
deficit is an inability to learn the predictive value of the context. Our
findings contribute to a broader understanding of the neural bases of
goal-directed action and its contextual regulation.

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Conflict of interest statement: Declaration of interests The authors declare no competing interests.

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