title: Differential role of the dorsal hippocampus, ventro-intermediate hippocampus, and medial prefrontal cortex in updating the value of a spatial goal.
abstract: Encoding of a goal with a specific value while performing a place navigation task involves the medial prefrontal cortex (mPFC) and the dorsal hippocampus (dHPC), and depends on the coordination between mPFC and the ventro-intermediate hippocampus (vHPC).The present work investigates the contribution of mPFC, dHPC, and vHPC when the rat has to update the value of a goal. Rats were trained to navigate to an uncued goal in order to release a food pellet in a continuous place navigation task. When they had reached criterion performance level in the task, they were subjected to a single "flash session" in which they were exposed to an aversive strobe light during goal visits instead of receiving a food reward. Just before the flash session, the GABA(A) agonist muscimol was injected to temporarily inactivate mPFC, dHPC, or vHPC. The ability to recall the changed value of the goal was tested on the next day. We first demonstrate the aversive effect of the strobe light by showing that rats learn to avoid the goal much more rapidly in the flash session than during a simple extinction session in which goal visits are not rewarded. Furthermore, while dHPC inactivation had no effect on learning and recalling the new goal value, vHPC muscimol injections considerably delayed goal value updating during the flash session, which resulted in a slight deficit during recall. In contrast, mPFC muscimol injections induced faster goal value updating but the rats were markedly impaired on recalling the new goal value on the next day. These results suggest that, contrary to mPFC and dHPC, vHPC is required for updating the value of a goal. In contrast, mPFC is necessary for long-term retention of this updating.
authors: Laboratory of Cognitive Neuroscience, Neural Basis of Spatial Cognition Team, Aix-Marseille Université, CNRS, Fédération 3C FR 3512, Marseille, France.
authors: Paul
authors: P
authors: De Saint Blanquat
authors: Vincent
authors: V
authors: Hok
authors: Etienne
authors: E
authors: Save
authors: Bruno
authors: B
authors: Poucet
authors: Franck A
authors: FA
authors: Chaillan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D006040:Goals; D006624:Hippocampus / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000187:drug effects; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology*
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol