Long-term memory、Plasticity of synaptic connections

For functional plasticity of synaptic transmission, which is considered an entity of short and medium-term memory was talk about one example of research。We are、We are also studies on the morphological plasticity of synapses, which is responsible for long-term memory。
One of the research results、It is the discovery of a protein called Cbln1 is essential to maintain and synapse formation even after maturity, not only at the time of development。Although the cerebellum has been responsible for the motor function、Not formed synapses in the cerebellum in mice deficient of Cbln1、It shows the severe gait disturbance。On the other hand、Cbln1 after the brain-deficient mice were mature、Injection of Cbln1 the cerebellum、Rapid synapse is formed、Gait disturbance is restored。While the molecule having the effect of forming a synapse between nerve cells to each other is called the synapse organizer、Cbln1 is one of them。
Also、One of the glutamate receptor、Delta 2 glutamate receptor (GluD2) was also found to cause a similar movement disorders and deficient mice also Cbln1-deficient mice。GluD2 and Cbln1 but is a molecule that was discovered separately in more than 20 years ago, respectively、At first glance these molecules unrelated to form a complex、It has led to the surprising discovery that has prompted the adhesion and maturation of between nerve cells。This research is expected to lead to the development of treatments for movement disorders caused by cerebellar disease。

3者の結合体がシナプス結合の接着剤

Although Cbln1 and GluD2 was found it is to have the effect of strongly induced synapse formation、If we look further、Also became clear that the interaction of the protein is required that neurexins。Cbln1 that nerve cells were synthesized and released、And Neurexin present in presynaptic membrane、By GluD2 present in postsynaptic membrane to form a tripartite complex、It seems to form and maintain the synapses that connect between nerve cells like a glue。
Also、Cbln1 and molecules similar to GluD2 is also in addition to the cerebellum、It has been found to be expressed, such as the hippocampus and cerebral cortex。By further advancing the elucidation of new synapse formation mechanism in the mature brain、It will be expected to contribute to further understanding of the basis for memory and learning brain function。
further、These studies、Synaptic abnormalities might lead to the treatment of dementia and neuropsychiatric diseases of aging that may be causing。Alternatively、Creation of fundamental technology that enables elucidation and control mechanisms functionally reconnect the neoplastic neuronal cells and existing neural、This means that there is also likely to lead to regenerative medicine。

PETへの期待

It is a model of the mouse is in so far our study of。Cells - although storage phenomena in the circuit level is considered to be used is basic principles in common with human、Again in order to understand the phenomenon of the human individual level、You will need to know the dynamics of the AMPA receptor in the human brain。Dementia and depression、From the fact that changes in the synaptic connections that connect between brain regions have been reported in psychiatric and neurological disorders such as schizophrenia、Although the amount of the AMPA receptor is changing is expected to strongly、Tools in Unfortunately the human brain can be visualized the glutamate receptor is not yet established。PET（Positron　Emission　Tomography:By using a positron emission tomography image)、Development of PET molecular probe that can be visualized to increase or decrease the AMPA receptor is desired in human brain。
We know that the AMPA receptor is an essential receptor for the formation of memory。For diagnosis and Pathogenesis of drug discovery and treatment development and psychiatric and neurological disorders of、Individual level and the cell - a tool to associate the phenomenon of the circuit level is required。

Hippocampus、The cerebral cortex、tonsil

In the storage of human individual level、The hippocampus, a brain area located in the limbic area has been noted。1950Patient HM, which were excised hippocampus for epilepsy treatment to age but is famous、The hippocampus is required for the formation of long-term memory associated with the episode at the individual level。And information of episodic memory went through the five senses (memory of the experience) will pass through the cerebral cortex、First to gather the incoming location is believed that it is the hippocampus。There is no doubt that it is engram of the first synapse is changed memory。
Then、Changes in the synapse will occur even where it receives the output from the hippocampus, such as the cerebral cortex。Even as it is engram of initially stored in the hippocampus、I think that there is no doubt that we moved to another location over time。Also、For those of hippocampus new stores、The original engram will cancel out。In memory associated with the fear, such as trauma、But also used the hippocampus in the context of the episode、Emotions and relationships and deep amygdala plays a major role。

細胞―回路レベルの記憶は脳内どこでも起きる

Memory cells - but we introduced the one end of the molecular level of research、When Understanding mechanisms of memory in the brain、It is important to find out whether you are in the target which level。
Cells - storage of molecular level、Hippocampus、tonsil、The cerebral cortex、Rather than be limited to the cerebellum、I think that basically I believe that occur synaptic plasticity in any synapses in the brain。But it is experimental well using a hippocampal neurons、I often not a phenomenon that occurs only in the hippocampus。When artificially stimulated to take out the nerve cells of other brain regions of the mouse、Plasticity happened memory of the synapse is formed。However、This is the only level in nerve cells。
It is not allowed to easily connect it to the nerve cell level individual level the story of。Even though the study of the memory of the brain、You must light of the what level study of the of。Also、I appreciated that、Progress degree of memory research is different at each level。
The study of the storage of the mechanism、At the molecular level - the bottom of the cell、3Why not split much than was revealed。In individual level、How to go to another location first in episodic memory that has been in the hippocampus、Material course of things like that and whether the recall of the memory occurs how the、I think that has not yet been elucidated also 10%。 <2016.03>

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