Systematic studies of retrograde amnesia started to emerge in the 1960s and 1970s.These were accompanied by the creation of animal models of human amnesia in an effort to identify brain substrates critical for slow consolidation.Meanwhile, neuropharmacological studies of selected brain areas began to shed light on the molecules possibly responsible for fast consolidation.
LTP, one of the best understood forms of synaptic plasticity, is thought to be a possible underlying process in synaptic consolidation.
The standard model of synaptic consolidation suggests that alterations of synaptic protein synthesis and changes in membrane potential are achieved through activating intracellular transduction cascades.
These molecular cascades trigger transcription factors that lead to changes in gene expression.
Synaptic consolidation is one form of memory consolidation seen across all species and long-term memory tasks.
Long-term memory, when discussed in the arena of synaptic consolidation, is memory that lasts for at least 24 hours.
An exception to this 24-hour rule is long-term potentiation, or LTP, a model of synaptic plasticity related to learning, in which an hour is thought to be sufficient.Synaptic consolidation is achieved faster than systems consolidation, within only minutes to hours of learning.Consolidation is distinguished into two specific processes, synaptic consolidation, which occurs within the first few hours after learning, and system consolidation, where hippocampus-dependent memories become independent of the hippocampus over a period of weeks to years.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.Memory consolidation was first referred to in the writings of the renowned Roman teacher of rhetoric Quintillian. that the interval of a single night will greatly increase the strength of the memory,” and presented the possibility that “… undergoes a process of ripening and maturing during the time which intervenes.” The process of consolidation was later proposed based on clinical data illustrated in 1882 by Ribot’s Law of Regression, “progressive destruction advances progressively from the unstable to the stable”. Burnham a few years later in a paper on amnesia integrating findings from experimental psychology and neurology.Coining of the term “consolidation” is credited to the German researchers Müller and Alfons Pilzecker who rediscovered the concept that memory takes time to fixate or undergo “Konsolidierung” in their studies conducted between 18.