July 7, 2022

Medical Trend

Medical News and Medical Resources

Eliminate memory: Japanese scholars use light to manipulate memory

Eliminate memory: Japanese scholars use light to manipulate memory



 

 

Eliminate memory: Japanese scholars use light to manipulate memory.

If you have an important document, where would you choose to put it? Is it placed on the shelf, stored in a drawer, or even hidden in a safe?

 

In fact, our brain is very good at doing these things. It often archives all kinds of memories and keeps them properly-memories first appear in one part of the brain, such as the hippocampus, and then transferred to another part for long-term storage. This process is It is called memory consolidation.

 

For a long period of time, humans have extremely limited cognition of the formation and consolidation of memory, not to mention erasing memories, covering them, or even manipulating memories as in movies.

Now, Yasunori Hayashi’s team at Kyoto University in Japan has successfully used new optogenetic technology to manipulate memory.

 

This technique hinders neural activity, the so-called long-term potentiation ( LTP ) , which could consolidate memory during sleep, thereby achieving the elimination of memory.

 

Recently, the research was published on the top international academic journal Science under the title : Stepwise synaptic plasticity events drive the early phase of memory consolidation .

 

Eliminate memory: Japanese scholars use light to manipulate memory.

 

 

Long-term potentiation (LTP) is a long-lasting enhancement phenomenon that occurs in the signal transmission of two neurons.

It can stimulate two neurons simultaneously, and then change the synaptic strength of the two. Since memory is thought to be encoded by changes in synaptic strength, LTP is generally regarded as one of the main molecular mechanisms that form the basis of learning and memory.

 

Since LTP can strengthen synapses through neural activity and is essential for memory formation, can we determine when and where memory is formed in the brain by examining when and which cells undergo LTP?

 

In fact, previous studies have shown that LTP can be destroyed by drugs, but this method is difficult to control and cannot block specific brain regions at specific time points of memory consolidation.

 

I believe many people are deeply impressed by the science fiction movie ” Men in Black ” starring Will Smith . In the movie, the agents use a flashing instrument to erase people’s memories.

 

Eliminate memory: Japanese scholars use light to manipulate memory.

 

 

Akihiro Goto , the first author of the study, said that the inspiration for this study proved to come from this movie .

They are doing something similar to those in black, except that they have replaced their black suits and sunglasses with white coats and safety goggles.

 

In this study, the research team noticed a protein that is essential for synaptic function, cofilin , and tried to manipulate its expression in the mouse brain through neuro-optical technology.

The researchers injected adeno-associated virus (AAV) , which is commonly used for gene delivery, into the brain of mice to express a fusion protein of cofilin and SuperNova photoreceptor protein.

When exposed to light, the SuperNova photoreceptor protein releases reactive oxygen species, making cofilin inactive.

 

Eliminate memory: Japanese scholars use light to manipulate memory.Experimental flowchart

 

Based on this, the research team was able to use neuro-optical technology to selectively eliminate long-term enhancement (LTP) of memory within a specific time window , thereby discovering that different stages of synaptic plasticity play different roles.

The first wave acts locally in the hippocampus, giving context specificity. In the second wave, during the same day’s sleep, these neurons are organized into synchronized firing sets.

Finally, during the second day of sleep, LTP in the anterior cingulate cortex is necessary to further stabilize memory.

 

Offline LTP in the hippocampus during sleep is necessary for memory consolidation

 

 

We all know that memories are initially encoded in the hippocampus and then transferred to the cerebral cortex for long-term storage. This means that LTP that occurs in the hippocampus is very important.

The research team found that when the mice illuminate their hippocampus immediately after learning a task, and then illuminate their hippocampus again during sleep after learning, the LTP that occurs in the hippocampus is interrupted, and these memories of the mice are lost. Will be lost.

 

Eliminate memory: Japanese scholars use light to manipulate memory.The LTP process of the hippocampus plays an important role in memory formation and memory consolidation

 

 

All in all, this study successfully eliminated the memory of mice through a new neuro-optical technology, and proved that in the early stage of memory consolidation, the precise location, time and characteristics of long-term potentiation (LTP) are essential for the formation of memory. 

In other words, memory can be eliminated through this directional lighting.

 

Yasunori Hayashi , the corresponding author of the study, said: “This new technology provides a way to separate the temporal and spatial memory formation in the brain at the cellular level.

It is hoped that this method will lead to a series of treatments for mental disorders. , Such as Alzheimer’s disease, learning disabilities and schizophrenia, etc.”

 

 

 

 

 

Reference:
https://www.science.org/doi/10.1126/science.abj9195
https://www.sciencedaily.com/releases/2021/11/211112121514.htm

Eliminate memory: Japanese scholars use light to manipulate memory

(source:internet, reference only)


Disclaimer of medicaltrend.org