Estudo do envolvimento do córtex perirrinal na reconsolidação da memória de reconhecimento de objetos

Abstract

Consolidated memories can become labile when reactivated and, to persist, must undergo a protein synthesis-dependent restabilization process called reconsolidation. The perirhinal cortex (PER) regulates the flow of information between different brain areas and although it has been implicated in object recognition memory (ORM) reconsolidation, the actual role of PER in this process remains controversial. Using the novel object recognition task, we investigated the conditions that constrain PER involvement in ORM reconsolidation. We found that bilateral intra-PER infusions of the protein synthesis inhibitor anisomycin caused amnesia when administered immediately after ORM reactivation in the presence of a familiar object but not when memory was reactivated in the presence of a new object, two familiar objects, or a new object alongside a familiar one. These results were also replicated by perirhinal NMDAr blockade with the selective NMDAr antagonist AP5. Immunofluorescence analyses revealed a prominent increase in PER ZIF268 expression only after ORM reactivation in the presence of a single familiar object. We also found that ZIF268 expression knockdown with antisense oligonucleotides hindered ORM reconsolidation. Our results indicate that partial perception of recognition cues during memory reactivation is a boundary condition for the participation of PER in ORM reconsolidation, and suggest that this process involves NMDAr activation and ZIF268 expression in that cortex.