The interplay between medial prefrontal cortex and hippocampus is required for the control of memory traces reactivation in the perirhinal cortex

MORICI FACUNDO; MAGDALENA MIRANDA; GALLO FRANCISCO; ZANONI SAAD MARIA BELEN; BEKINSCHTEIN, PEDRO; NOELIA V WEISSTAUB

Buenos Aires

Congreso; 2nd FALAN Congress; 2016

FALAN/SAN

In the recent years, it has been postulated that mPFC interacts with thehippocampus during recognition memory retrieval, particularly when retrievalis guided by contextual information. We have shown that blockingtype 2A serotonin receptor (5HT2Ar) in the mPFC and activity in the hippocampusin contralateral hemispheres impairs the resolution of an object-in-context recognition memory task. Information regarding the identityof the object could be stored in other structures such as the perirhinalcortex (PRH). We postulate that the interaction between mPFC and thehippocampus is required to control the reactivation and reconsolidationof memory traces in the PRH. If this is the case, then manipulation of thisnetwork might aect reconsolidation in this structure. To test this idea, wemade contralateral and ipsilateral infusions of a 5HT2Ar antagonist inmPFC and muscimol in the hippocampus before memory retrieval/reactivation.After reactivation, protein synthesis in the PRH was interruptedwith emetine. We found that in the ipsilateral group, emetine blockedmemory reconsolidation, but only for the object that was in contextualmismatch with the retrieval context. Interestingly, contralateral infusionsmade memories for both objects susceptible to the action of emetine.Our results suggest that the interaction between mPFC and the hippocampuscontrols the reactivation (and therefore the reconsolidation) ofthose memory traces competing during the retrieval phase.