Memory consolidation is a category of processes that stabilize a memory trace after its initial acquisition. Recently, a third process has become the focus of research, reconsolidationin 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. He noted the "curious fact… that the interval "Daniel consolidating" a single night will greatly increase the strength of the memory," and presented the possibility that "… the power of recollection. This idea was elaborated on Daniel consolidating William H.
Burnham a few years later in a paper on amnesia integrating findings from experimental psychology and neurology. Systematic studies of anterograde amnesia started to emerge in the s and s. The case of Henry Molaisonformerly known as patient H. After Molaison underwent a bilateral medial temporal lobe resection to alleviate epileptic symptoms the patient began to suffer from memory impairments.
Molaison lost the ability to encode and consolidate newly learned information leading researchers to conclude the medial temporal lobe MTL was an important structure involved in this process. These studies were accompanied by the creation of "Daniel consolidating" models of human amnesia in an effort to identify brain substrates critical for slow consolidation. Meanwhile, neuropharmacological studies of selected brain areas began to Daniel consolidating light on the molecules possibly responsible for fast consolidation.
Providing additional support is the study of functional brain activity in humans which has revealed that the activity of brain regions changes over time after a new memory is "Daniel consolidating." Synaptic or late-phase LTP is one form of memory consolidation seen across all species and long-term memory tasks.
Long-term memory "Daniel consolidating," when discussed in the context of synaptic consolidation, is memory that lasts for at least 24 hours. An exception to this hour rule is long-term potentiationor LTP, a model of synaptic plasticity related to learningin which an hour is thought to be sufficient. Synaptic consolidation is Daniel consolidating faster than systems consolidation, within only minutes to hours of learning in goldfish.
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. The result of the gene expression is the lasting alteration of synaptic proteins, as well as synaptic remodeling and growth. In a short time-frame immediately following learning, the molecular expression and process of both transcription factors and immediate early genesare susceptible to disruptions.
Disruptions caused by specific drugs, antibodies and gross physical trauma can block the effects of synaptic consolidation. LTP can be thought of as the prolonged strengthening of synaptic transmission and is known to produce increases in the neurotransmitter production and receptor sensitivity, lasting minutes to even days.
The process of LTP is regarded as a contributing factor to synaptic plasticity and in the growth of synaptic strengthwhich are suggested to underlie memory formation. LTP is also considered to be an important mechanism in terms of maintaining memories within brain regions,  and therefore is thought to be involved in learning. Specifically, NMDA-receptor antagonists appear to block the induction of both LTP and fear conditioning and that fear conditioning increases amygdaloidal synaptic transmission that would result in LTP.
Synaptic consolidation, when compared to systems consolidation which is said to take weeks to months to years to be accomplishedis considerably faster. Distributed learning has been found to enhance memory consolidation, specifically for memory.
Experimental results suggest that distributing learning over the course of 24 hours decreases the rate of forgetting compared to massed learningand enhances relational memory consolidation. When interpreted in the context of synaptic consolidation, mechanisms of synaptic strengthening Daniel consolidating depend on the spacing of memory reactivation to allow sufficient time for protein synthesis to occur, and thereby strengthen long-term memory. Protein synthesis plays an important role in the formation of new memories.
Studies have shown that protein synthesis inhibitors administered after learningweaken memory, suggesting that protein synthesis is required for memory consolidation. Additionally, reports have suggested that the effects "Daniel consolidating" protein synthesis inhibitors also inhibit LTP.
Daniel consolidating Consolidation is the second form of memory consolidation. It is a reorganization process in which memories from the hippocampal region, where memories are first encodedare moved to the neo-cortex in a more permanent form of storage.
The model of systems consolidation has been summarized by Squire and Alvarez ;  it states that when novel information is originally encoded and registered, memory of these new stimuli becomes retained in both the hippocampus and cortical regions.
Memory is retained in the hippocampus for up to one week after initial learningrepresenting the hippocampus-dependent stage. Since the hippocampus can only support Daniel consolidating temporarily the remaining activation will be seen only in the neocortex which is able to support memory indefinitely. Squire and Alvarez took the temporally graded nature of patients with retrograde amnesia as support for the notion that once a connection has been established within the neocortex the hippocampus is no longer required, but this process is and extends for several years.
Squire and "Daniel consolidating" also proposed the that MTL structures play a role in Daniel consolidating consolidation of memories within "Daniel consolidating" neocortex by providing a binding area for multiple cortical regions involved in the initial encoding of the memory.
After this has occurred the MTL directs information towards the neocortex to provide a permanent representation of the memory. Multiple trace theory MTT builds on the distinction between semantic memory and episodic memory and addresses perceived shortcomings of the standard model with respect to the dependency of the hippocampus. MTT argues that the hippocampus is always involved in the retrieval and Daniel consolidating of episodic memories.
As memories age there are long-term interactions between the hippocampus and neo-cortex and this leads to the establishment of aspects of memory within structures aside from the hippocampus. However, Nadel and Moscovitch have shown that the hippocampus was involved in memory recall for all remote autobiographical memories no matter of their age.
Haist, Gore, and Mao, sought to examine the temporal nature of consolidation within the hippocampus to test MTT against the standard view. They claim that advances in the functional magnetic resonance imaging have allowed them to improve their distinction between Daniel consolidating hippocampus and the entorhinal cortex which they claim is more enduring in its activation from remote memory retrieval.
Nadel and Moscovitch argued that when studying the structures and systems involved in memory consolidation, semantic memory and episodic memory need to be distinguished as relying on two different memory systems. When episodic information is encoded there are semantic aspects of the memory that are encoded as well and this is proposed as an explanation of the varying gradients of memory loss seen in amnesic patients.
Learning can be distinguished by two forms of knowledge: Declarative information includes the conscious recall of facts, episodes, and lists, and its storage typically connected with the MTL and the hippocampal systems as it includes the encoding of both semantic and episodic information of events.
Procedural knowledge however has been said to function separate from this system as it relies primarily on motor areas of the brain. Amnesic patients have shown retained ability to be trained on tasks and exhibit learning without the subject being aware that the training had ever taken place. Squire has proposed the procedural knowledge Daniel consolidating consolidated in some cases by Daniel consolidating extrapyramidal motor system.
The amygdalaspecifically the basolateral region BLA is involved in the encoding of significant experiences and has been directly linked to memorable events. It is suggested that epinephrine affects memory consolidation by activating the amygdala and studies have shown that antagonism of beta-andrenoreceptors prior to injection of epinephrine will block the retention of memory effects seen previously.
Rapid eye movement REM sleep Daniel consolidating been thought of to be an important concept in the overnight learning in humans by establishing information in the hippocampal and cortical regions of the brain.
It has been proposed that since the brain is in a non-memory encoding state during sleep, consolidation would be unlikely to occur. Recent studies have examined the relationship between REM sleep and procedural learning consolidation. In particular studies have been done on sensory and motor related tasks.