A NEAT Discovery About Memory

Memory in older adults and elderly begins to diminish and scientists previously have failed to understand why. A recent study at the University of Alabama uncovered a non-coding piece of RNA known as NEAT1 which plays a role in memory formation. Coding parts of RNA send messages throughout the cell as proteins while non-coding parts also hold instructions but they have never been completely understood. Scientists have found that “NEAT1 is a tissue-specific, non-coding RNA… most associated with learning and memory.” More specifically, it regulates memory formation.

Learning is more difficult when NEAT1 is active “but when presented with an outside learning experience, it turns off, allowing the brain to learn from the outside stimulus.” Researchers explain this similarly to how a car won’t move when the engine is on and the breaks are being used. It isn’t until the breaks are off that the car will move. 
Doctors wondered if since NEAT1 plays a role in the formation of memories, perhaps they also interact with the decline of memory seen in adults and the elderly. NEAT1 interacts with a gene called c-FOS and their interactions increase with an aging brain, meaning that NEAT1 disrupts memory formation in aging brains. 

In order to test this, researchers used tools to turn off NEAT1 in mice and “With NEAT1 off, the mice demonstrated normal abilities in learning and memory.” Another experiment showed that when the levels of NEAT1 were increased in younger mice, their ability to learn and form memories decreased. 

This research is not only a huge breakthrough for the understanding of memory loss with increasing age but also a very big discovery for the impacts of non-coding RNA. I think it is impressive that scientists were able to find this specific section of RNA and were able to discover its association with memory. This information could play a key role in developing a medication to decrease memory loss. Perhaps in the years to come, CRISPR could remove this non-coding area of RNA all together, fixing the problem of memory loss. 

https://www.sciencedaily.com/releases/2019/07/190702152813.htm

Newborn neurons keep memories crisp and fresh

There have been multiple studies performed to understand the birth of new neurons is substantial to memory formation. Specifically, scientists believe that neurogenesis are a component to pattern separation- the ability to distinguish between similar experiences or events based on senses such as smell or a visual landmark. 

Now, scientists are able to produce deficits in pattern separation in animals by blocking neurogenesis using x-ray radiation to kill certain population of cells in the brain where the dentate granule neurons are located. However, this technique does not pinpoint which actual cells of which are being recorded from.

 A new study with mice explains how newly born neurons and mature dentate granule neurons differ in activity. Researchers at Columbia University used mice that have been genetically engineered to convey fluorescent molecules of neurons up to 6 weeks old. Scientists blocked the newly born neurons with the technique of optogenetics- a tool used to pretty much turn a cell on and off like the switch of a light. When scientists performed this technique, the mice were not able to distinguish which between 2 different chambers; one where they were mildy zapped on their leg and the other where no zapping occurred. The experimental mice expressed distress when placed in either chambers, whereas the control group only expressed it within the chamber they were shocked- which supports the idea that neurogenesis corresponds to pattern separation. 

Another study was conducted when the mice were placed on a treadmill and given specific stimuli as running through different environments with the use of different sounds, visual clues, and scents. After examining the activity in the mices' brains, the researchers observed that mature cells' firing were fine tuned into a specific location, whereas the locations of the young cells firing were arbitrary, in which presumes that as they mature the cells will develop a more designated firing location. It's not surprising that the mature cells had specific firing locations, for it corresponds to the model of neurogenesis and memory formation. The task for the young neurons isn't so much to carry new information about spatial location and environmental context in certain occurrences, but moreso temper the activity the older cells responding to that information. 

Research is now suggesting that deficits in pattern separation- likely in people with anxiety, depression, and PTSD may undergo difficulty in distinguishing between past fearful and sad events and novel experiences. Other evidence suggests that treatments such as antidepressants and exercise can help people with these conditions to maintain a better separation between the past and the present. 

http://www.sciencemag.org/news/2016/03/newborn-neurons-keep-memories-crisp-and-fresh