Memory consolidation

Memory consolidation is a category of biological processes in the brain that stabilize a memory over time after it is initially learned. A memory trace is the biological change in neural circuits caused by acquisition of new information. Consolidation is distinguished into two specific processes. The first, synaptic consolidation, which is thought to correspond to late-phase long-term potentiation, occurs on a small scale in the synaptic connections and neural circuits within the first few hours after learning. The second process is systems consolidation, occurring on a much larger scale in the brain, with gradual reorganization and reduced reliance on the hippocampus and strengthening of distributed cortical networks over a period of weeks to years. This involves several mechanisms including molecular, synaptic, and systems-level processes that stabilize the neural ensemble (engram) that is thought to represent the newly formed memory. Recently, a third process has become the focus of research, reconsolidation, in which previously consolidated memories can be made labile again through reactivation of the memory trace.