Memories could be RE-AWOKEN in Alzheimer’s sufferers: Scientists reactivate brains of dementia-plagued mice with lasers – paving the way to a human cure

Home / Mental health / Memories could be RE-AWOKEN in Alzheimer’s sufferers: Scientists reactivate brains of dementia-plagued mice with lasers – paving the way to a human cure
August 01, 2017August 1, 2017
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  • Lost memories in Alzheimer’s patients could be brought back with lasers
  • Research team at Columbia University claims memories are not lost but difficult to access
  • Looked at two groups of mice, one with dementia-like disease, one without
  • Studied their brain when they were given memory tests and found the memories are recalled incorrectly
  • Also found that lasers stimulated neurons related to memory, causing lost memories to be re-awoken in the mice 

Lost memories could be brought back in patients with Alzheimer’s, as new research finds that the disease might not destroy them altogether as previously believed.

It has long been thought that Alzheimer’s disease, which is the most common form of dementia, completely erases a sufferer’s memories over time.

However, according to a new study conducted on a group of mice at Columbia University, memories might not be completely wiped out by the disease, but instead made harder to access.

The new data also suggests these ‘lost’ memories can be reawakened by artificially activating the neurons where they are stored.

Alzheimer’s is a progressive degenerative brain disease that usually occurs in people in middle or old age that is thought to destroy memory and other basic functions.

The disease is characterized by clumps of protein called beta-amyloid, which are thought to damage and destroy brain cells in people with the disease.

Lost memories could be brought back in patients with Alzheimer's, as new research finds that the disease might not destroy them altogether as previously believed (stock image)

Lost memories could be brought back in patients with Alzheimer’s, as new research finds that the disease might not destroy them altogether as previously believed (stock image)

Researchers found that by zapping a certain part of the brain associated with memory storage, they were able to force mice to recall memories that had previously been lost.

The team looked at two groups of mice, one healthy, and one with a condition that resembles Alzheimer’s in humans.

In these mice, they genetically engineered neurons to glow yellow when activated during memory storage, and to glow red when activated during memory recall.

PAUSES IN SPEECH MAY INDICATE ALZHEIMER’S

Pauses in speech and taking longer to talk may be early signs of mental decline, research revealed earlier this month.

People with a family history of Alzheimer’s disease who are at-risk of developing the condition are less able to express their ideas and have reduced ‘fluency’ when speaking, a study found.

They also use words such as ‘it’ or ‘they’ rather than specific names for things and speak in shorter sentences, the research adds.

Julie Liss, a speech expert at Arizona State University, who was not involved in the study, said: ‘Those are all indicators of struggling with that computational load that the brain has to conduct’

Around 47 million people worldwide have dementia, with Alzheimer’s disease being the most common form of the condition.

Their memory was then tested twice. First, mice were exposed to a lemon scent and given an electric shock. A week later they were exposed to the same scent, which caused the healthy mice to pause, but the diseased mice not to react.

This suggested those mice with the Alzheimer’s-like disease didn’t remember the link between the smell and the shock as strongly.

Researchers also looked at their brain scans during the tests, and found that the brain region that records memories, the hippocampi, displayed signals that explained how mice were acting.

In mice without the disease, they saw the red and yellow neurons overlapped, meaning they were retrieving the memory of the shock in the same place it was stored.

But in mice with the Alzheimer’s-like disease, different cells glowed red during the recall, showing that they might have been coming up with the wrong memories.

According to lead author Dr Christine Denny, these results might explain why people with Alzheimer’s sometimes experience false memories.

The mouse experiments could show that people may be sending the retrieval signal to the wrong brain cells.

Following the initial round of testing, the research team used a genetic engineering technique called optogenetics on the mice to reactivate the memory of the shock.

According to lead author Dr Christine Denny, these results might explain why people with Alzheimer's sometimes experience false memories. They also show that the memories which were thought to be lost still exist in the brain

According to lead author Dr Christine Denny, these results might explain why people with Alzheimer’s sometimes experience false memories. They also show that the memories which were thought to be lost still exist in the brain

The technique is done by shining a blue fibre optic cable into the brain to stimulate the memory-storing neurons. This prompted the mice to freeze again when introduced to the lemon scent.

The results showed that these memories, previously thought to be lost, may exist in the brain, and could be recovered.

However, currently optogenitics isn’t something that can be used on humans because it’s not safe to use lasers on neurons or brain cells. However, in the future, Dr Denny suggests this research could lead to drugs or techniques that stimulate memories deep in the brain, which could help Alzheimer’s patients.

The techniques could also potentially help people recover other memories as well, such as at a crime scene or even those from childhood.

But, because of being unable to pinpoint exactly where a memory is stored, it is unlikely people will be able to bring back specific memories. Additionally, some neurons could hold multiple memories, including bad ones.