Achi news desk-
Dr Shuzo Sakata, an expert on brain function and pathology, will lead the project which seeks to better understand the link between sleep and Alzheimer’s disease, in the hope of finding new ways to prevent the disease.
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Research has shown that changes in sleep patterns are common among people with dementia, even in its early stages.
However, the link between sleep and dementia is still a mystery.
Dr Sakata will examine how sleep disruption affects the brain’s immune cells – known as microglia.
Microglia protect the brain by removing debris, including the harmful amyloid protein that builds up in Alzheimer’s disease.
During sleep, microglia in a healthy brain extend their arms and increase their calcium levels.
When there is a lack of sleep, however, the microglia shrink their arms and become a round, amoeba-like shape.
It is not known how amyloid is related to these changes in calcium.
Dr Sakata hopes the research will eventually extend to studying the brains of human patients, but admits this “could be a long way off”.
For now, he will use advanced imaging techniques to see inside the immune cells on multiple regions of the brain in mouse models of Alzheimer’s.
This will enable researchers to evaluate how amyloid affects calcium levels in microglia in sleeping and waking states, and how sleep deprivation affects these calcium levels.
Dr Sakata said this project will be the first to “bridge the gap” between sleep, microglia, and dementia, which have tended to be studied separately.
He said: “People have looked at the relationship between Alzheimer’s and sleep, and for Alzheimer’s and microglia there are many studies.
“There is also some imaging research into the relationship between sleep and microglia in healthy people.
“But nobody has looked at these three components together – and, if I’m lucky, I might be able to find something that can lead to a new treatment.”
He added that there appears to be a “bi-directional” relationship between sleep and dementia, in that the build-up of amyloid plaques in the brain leads to abnormal sleep patterns that “stimulate disease progression”, but at the same time disrupt on sleep the potential to fuel the accumulation of amyloid deposits.
“That’s still a hypothesis, but we want to explain how microglia contribute to these bidirectional interactions,” said Dr. Sakata.
The project is one of two new studies in Scotland funded by Alzheimer’s Disease UK in its latest £4 million research investment.
In addition, the charity has allocated £30,000 to a project at Edinburgh University which investigates how the blood-brain barrier is damaged by the diseases that cause dementia.
The study will be led by Dr Paula Beltran-Lobo, who said she was excited to be relocating from London to Scotland to pursue her work – describing it as a “centre of excellence” for dementia research.
Dr Beltran-Lobo will focus on star-shaped cells called astrocytes that act as bridges, connecting neurons in the brain to the vascular cells in the blood vessels.
The blood-brain barrier is a membrane that controls the movement of molecules, such as nutrients, from the bloodstream into the brain.
It is known that when a protein called tau accumulates in astrocytes during the onset of diseases such as Alzheimer’s and Frontotemporal dementia, it can disrupt their function and cause the blood-brain barrier to leak.
“That happens early in the disease and it has devastating consequences for the neurons because they don’t have enough nutrients, or some of the accumulations in the brain can’t be cleared,” said Dr Beltran-Lobo .
Little is known about how tau protein accumulates in astrocytes during disease, or how it affects the cell’s role in keeping the blood brain barrier healthy.
By using brains donated from people who had high levels of tau protein when they died, Dr Beltran-Lobo hopes to gain a better understanding of how tau disrupts the blood brain barrier.
Dr Beltran-Lobo said: “Most of the research has always been focused on what happens to the neurons, and we are only beginning to look at what happens to the support system around neurons that we are starting to look at.
“We are at the beginning and these diseases are very complex, but if we can prevent these harmful changes from occurring in the astrocytes we may be able to develop treatments that target the disease in the earlier stages.
“And because we’re looking at a treatment that we could give through the bloodstream, it might be easier than developing treatments that target the brain directly.”
Dr Julia Dudley, head of strategic programs at Alzheimer’s Research UK, added: “In the UK alone, there are almost a million people living with dementia.
“So there has never been a more pressing need to prevent or treat the diseases that cause this devastating condition.
“Alzheimer’s Research UK is proud to support research that builds a better understanding of how these diseases develop in the brain which could lead to the breakthroughs that people with dementia deserve and need.
“It is vital that we continue to invest in studies like these to accelerate progress towards a cure, and to end the fear, harm and heartbreak of dementia.”
