5-HT2a receptor in mPFC controls context-guided reconsolidation of long- term object memory in perirhinal cortex

JUAN FACUNDO MORICI; MIRANDA, MAGDALENA; FRANCISCO GALLO; MARÍA BELÉN ZANONI; BEKINSCHTEIN, PEDRO; WEISSTAUB, NOELIA V.

Mar del Plata

Congreso; Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2017

Sociedad Argentina de Investigación en Neurociencias

The object recognition memory retrieval is a complex process that required theinteraction of multiples structures. It has been proposed that mPFC interactswith the hippocampus during contextual-guided versions of the spontaneousobject recognition paradigm. Using a pharmacological disconnectionexperiment, we have shown that mPFC 5-HT2aR modulation and hippocampus(HIP) interacts in an ipsilateral way during the resolution of an object-in-contextrecognition memory task. Since the information regarding the identity of theobject could be stored in other structures such as the perirhinal cortex (PRH)then, the mPFC-HIP interaction could control the reactivation/reconsolidation inthe PRH. To test this idea, we infused a 5-Ht2aR antagonist (MDL) in mPFC beforethe reactivation phase and immediately after a protein synthesis inhibitor (EME)in the PRH or dorsal dHIP. We also evaluate the interaction between the ventralhippocampus (vHIP) and the mPFC using a disconnection approach. We infusedMDL in mPFC and muscimol in the vHIP before the retrieval and EME in the PRHafter the reactivation session. We found that blocking 5-HT2aR signaling in themPFC aects the reconsolidation in the PRH but not in the dHIP. In thedisconnection experiment, only contralateral infusions made memories for bothobjects susceptible to the action of EME. Our results suggest that the interactionbetween mPFC 5-HT2a modulation and HIP activity controls the reconsolidationof object memory traces in PRH during the retrieval phase.