RT Journal Article
SR Electronic
T1 A Role for Medial Prefrontal Dopaminergic Innervation in Instrumental Conditioning
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 6599
OP 6606
DO 10.1523/JNEUROSCI.1234-09.2009
VO 29
IS 20
A1 Fabien Naneix
A1 Alain R. Marchand
A1 Georges Di Scala
A1 Jean-Rémi Pape
A1 Etienne Coutureau
YR 2009
UL http://www.jneurosci.org/content/29/20/6599.abstract
AB To investigate the involvement of dopaminergic projections to the prelimbic and infralimbic cortex in the control of goal-directed responses, a first experiment examined the effect of pretraining 6-OHDA lesions of these cortices. We used outcome devaluation and contingency degradation procedures to separately assess the representation of the outcome as a goal or the encoding of the contingency between the action and its outcome. All groups acquired the instrumental response at a normal rate, indicating that dopaminergic activity in the medial prefrontal cortex is not necessary for the acquisition of instrumental learning. Sham-operated animals showed sensitivity to both outcome devaluation and contingency degradation. Animals with dopaminergic lesions of the prelimbic cortex, but not the infralimbic cortex, failed to adapt their instrumental response to changes in contingency, whereas their response remained sensitive to outcome devaluation. In a second experiment, aimed at determining whether dopamine was specifically needed during contingency changes, we performed microinfusions of the dopamine D1/D2 receptor antagonist flupenthixol in the prelimbic cortex only before contingency degradation sessions. Animals with infusions of flupenthixol failed to adapt their response to changes in contingency, thus replicating the deficit of animals with dopaminergic lesions in Experiment 1. These results demonstrate that dissociable neurobiological mechanisms support action–outcome relationships and goal representation, dopamine signaling in the prelimbic cortex being necessary for the former but not the latter.