Role of calcium-permeable AMPA receptors in memory consolidation, retrieval and updating

Abstract

The role of the calcium-permeable AMPA receptor (CP-AMPAR) in synaptic plasticity is well established. CP-AMPAR is believed to be recruited to synapse when the memory trace is in a plastic state; however, the direct implications of its expression for memory processes is less known. Here, we investigated the contribution of CP-AMPAR expressed in the basolateral amygdala (BLA) and hippocampus (HPC) in consolidation of different types of memory, retrieval and memory update. We showed that CP-AMPAR blockade by NASPM in the BLA and HPC impaired fear memory consolidation. NASPM infusion in the HPC also impaired spatial memory consolidation in the water maze, whereas consolidation of object location memory was not affected. We found evidence of the CP-AMPAR involvement in the BLA and in the HPC upon memory retrieval. Furthermore, memory update was affected by NASPM infusion in the HPC in both immediate shock deficit and water maze reversal learning tasks. Our data indicate that the activity of CP-AMPAR in the BLA and HPC is required for the consolidation of emotional memories. Moreover, this receptor activity is required for memory retrieval in the BLA and HPC. These findings support that CP-AMPAR has a key function in memory states in which plastic changes are presumably higher, such as the beginning of memory consolidation, and retrieval-induced updating.

Keywords: Amygdala; Calcium-permeable AMPA receptor; Consolidation; Hippocampus; Retrieval-induced updating.