AMPA receptor plasticity in retrieval, reconsolidation and post-retrieval extinction of memories

Abstract

Learning and memory are evolutionary evolved ‘survival factors’. They are fundamental in nature, as most species use stored information related to experience to adapt to constantly changing environments. When experiences are aversive (fearful), they should be avoided upon renewed contact. Thus, coupling environmental stimuli to aversive events enables the individual to respond adequately later in time. This involves implicit (non-declarative) learning in which the resulting associative memories can be recalled refl exively and may have lifetime persistence. Sometimes this learning can be maladaptive, resulting in a hyper-responsive system, in which stimulus-induced recall of memory leads to excessive fear and anxiety. In order to develop new therapeutic strategies to treat such disorders, it is important to understand the neural mechanisms of the capacity to encode, store, consolidate, retrieve and erase information. In this chapter we will touch upon synaptic plasticity mechanisms that underlie memory formation, and focus on the role of AMPA receptor (AMPAR) plasticity in the amygdala and hippocampus during the retrieval, destabilization and subsequent restabilization of memory.