Processing of an aversive memory: early and late role of the Medial Prefrontal Cortex

GONZALEZ CAROLINA; KRAMAR CECILIA; CYNTHIA KATCHE; ROSSATO JANINE; FERNANDO GARAGOLI; TOMAIUOLO MICOL; HOLMBERG JOSEFINA; DORMAN GUIDO; CAMMAROTA MARTIN; MEDINA H. JORGE

Florencia

Congreso; 8th IBRO World Congress of Neuroscience; 2011

Systems consolidation establishes that memories are initially stored in the hippocampus and later transferred to the cortex for persistent storage. Nevertheless, an alternative view proposes that the neocortex may have a crucial role from initial steps of memory formation. Using c-Fos immunocytochemistry, we studied the activation of cortical areas induced by an inhibitory avoidance (IA) training in rats. We found that after a strong training, which generates a persistent memory, several cortical regions are selectively activated 1, 12 and 24h after training, including the prelimbic and anterior cingulate cortices. Since this activation might indicate sites involved in memory processing, we decided to study the role of mPFC in the formation and persistence of aversive memories. We infused anisomycin or emetine (protein synthesis inhibitors) into the prelimbic cortex near the time of training and 12h later. These treatments produced amnesia for IA learning measured 2, 7 or 14 days after acquisition. However, protein synthesis inhibitors appeared not to affect memory when given 6 or 24h after training. These results indicate that protein synthesis during both time periods (around training and 12h after training) are necessary for memory consolidation of this task and indicate a crucial role for mPFC in memory processing at early and late stages.