The mediodorsal thalamus supports adaptive responding based on stimulus-outcome associations

Morceau S(1), Faugère A(1), Coutureau E(1), Wolff M(1).

Author information:
(1)Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France.

The ability to engage into flexible behaviors is crucial in dynamic
environments. We recently showed that in addition to the well described role of
the orbitofrontal cortex (OFC), its thalamic input from the submedius thalamic
nucleus (Sub) also contributes to adaptive responding during Pavlovian
degradation. In the present study, we examined the role of the mediodorsal
thalamus (MD) which is the other main thalamic input to the OFC. To this end, we
assessed the effect of both pre- and post-training MD lesions in rats performing
a Pavlovian contingency degradation task. Pre-training lesions mildly impeded
the establishment of stimulus-outcome associations during the initial training
of Pavlovian conditioning without interfering with Pavlovian degradation
training when the sensory feedback provided by the outcome rewards were
available to animals. However, we found that both pre- and post-training MD
lesions produced a selective impairment during a test conducted under extinction
conditions, during which only current mental representation could guide
behavior. Altogether, these data suggest a role for the MD in the successful
encoding and representation of Pavlovian associations.

© 2022 The Author(s).

DOI: 10.1016/j.crneur.2022.100057
PMCID: PMC9587292
PMID: 36281274

Conflict of interest statement: The authors declare that they have no known
competing financial interests or personal relationships that could have appeared
to influence the work reported in this paper.

Auteurs Bordeaux Neurocampus