Retrosplenial cortex integrity is required during acquisition for its participation in an object- recognition memory

DE LANDETA, ANA BELÉN; KATCHE, CYNTHIA; PEREYRA, MAGDALENA; MEDINA, JORGE H.

Congreso; XXXIII Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias; 2018

Several studies demonstrated that the retrosplenial cortex (RSC) is involved in navigation andcontextual memory. Recently, we found that the RSC is also Required for the processing of anobject-recognition memory. We inactivated this structure with muscimol infusions performed at different time points of that task and found that memory was impaired when the RSC was inactivated during consolidation or retrieval. In this case, animals did not explore preferentially the novel object. In contrast, inactivating the RSC during acquisition did not interfere with recognition memory and animals explored preferentially the novel object. Taking into account these results, we evaluated whether inactivating the RSC during acquisition interferes with its recruitment in memory processing. Animals were subjected to a double-inactivation of the RSC, in order to affect both acquisition and consolidation or both acquisition and retrieval. We predicted that the first injection would disengage the RSC from memory processing, thus leaving consolidation and retrieval intact, despite the second injection targeting them. Our results showed that this was indeed the case as double-injected animals exhibited intact recognition memory. We thus propose that the RSC is recruited to process the object-recognition memory, only if it is active during the acquisition of that memory. On the contrary, when the RSC is not active during acquisition, other brain structures may take control of memory processing.