... AND HOW A GOOD NIGHT’S REST MAY BE KEY TO BEATING DEMENTIA

MOST of us feel groggy and grumpy after a bad night, but researchers at Imperial College London are investigating whether poor sleep could be having a more serious impact on the brain by increasing the risk of dementia.

It’s known that people with Alzheimer’s and other forms of dementia tend to have disrupted sleep patterns, and recent studies have shown that poor sleepers are more likely to develop the condition.

Last year, US researchers showed that disrupted sleep increased the levels of toxic amyloid in the brain, which may contribute to the development of Alzheimer’s.

But it’s not clear which comes first: is poor sleep causing dementia, or is it simply an early sign of the underlying disease?

To solve this puzzle, sleep expert Professor Bill Wisden, chair in molecular neuroscience, has teamed up with brain specialists as part of the UK Dementia Research Institute.

‘Nobody really knows what the purpose of sleep is,’ explains Professor Wisden. ‘We have to do it every night and it’s essential for health — but we haven’t found out what it’s for!’ He and his colleagues are focusing on the concept of ‘brain washing’ — the natural movement of fluid that flushes out waste chemicals produced by brain cells, including toxic amyloid proteins associated with Alzheimer’s.

The process was first discovered in 2013 by a team of US scientists and is much more active as we sleep.

Using laboratory mice, the Imperial College team are investigating how patterns of brainwaves and ‘brainwashing’ change if

the animals are deprived of sleep, and whether this leads to a build-up of toxic Alzheimer’s proteins. ‘It’s a very gentle experiment,’ he says. ‘Just as you or I will stay up late for hours if we’re watching an exciting TV box set, mice will stay awake if we give them interesting new objects like a Lego brick or a pencil every hour or so.’

The researchers then measure the animals’ brainwaves and use cutting-edge microscope techniques to see how amyloid proteins are moving inside the brain.

Not only does Professor Wisden hope that the study will answer the scientific question of what’s going on as the brain cleans itself out during sleep, he also plans to turn the findings into a potential treatment.

Working with his Imperial College colleague, electrical engineer Dr Nir Grossman, he’s testing a machine that can manipulate brainwaves non-invasively using electrical currents.

They plan to induce the patterns of brainwaves found during ‘brainwashing’ sleep to get rid of amyloid and improve memory in people with early stage dementia. So far, the technique has only been tested on mice but the team will shortly be starting human clinical trials.

‘We’re increasingly realising that dementia and its causes are complex — there are multiple factors at play and sleep is part of that jigsaw,’ says Dr Andrew Sommerlad, a research fellow in psychiatry at University College London.

‘This approach has the potential to tell us more about dementia and give us new ideas for treatments in the future.’