Memory Consolidation 21

Memory consolidation is a multifaceted concept. At a minimum, it refers to both cellular consolidation and systems consolidation. Cellular consolidation takes place in the hours after learning, stabilizing the memory trace—a process that may involve structural changes in hippocampal neurons. Systems consolidation refers to a more protracted process by which memories become independent of the hippocampus as they are established in cortical neurons—a process that may involve neural replay. Both forms of consolidation may preferentially unfold whenever the hippocampus is not encoding new information, although some theories hold that consolidation occurs exclusively during sleep. In recent years, the notion of reconsolidation has been added to the mix. According to this idea, previously consolidated memories, when later retrieved, undergo consolidation all over again. With new findings coming to light seemingly every day, the concept of consolidation will likely evolve in interesting and unpredictable ways in the years to come.