Dementia research news - spring 2018

2. Keep snoozing


Following on from our winter feature ‘Can you sleep your way to a healthier brain?’ more early-stage research has come out that looks into any links between sleep and brain health.

Researchers at the Washington University School of Medicine in the US recruited a small group of eight volunteers to sleep for science. However, before the volunteers could enjoy a good night’s rest they were kept awake for one whole night. Lead researchers Brendan Lucey and Randall Bateman sampled the cerebrospinal fluid (CSF) of each volunteer after one night awake and also after a restful night.

CSF is the liquid that surrounds the brain and spinal cord and that fills chambers within the brain. It can drain waste products from the brain, so seeing what is in the CSF can tell us how the brain is reacting to something.

The researchers found that, when they kept volunteers awake overnight, they had a third more amyloid-beta in their CSF than when they let them sleep. Amyloid-beta is a protein that is present in everyone’s brains, but in Alzheimer’s disease it builds up and forms dense clumps called ‘plaques’.

This led to the question: Does a lack of sleep cause more amyloid-beta to be made, or does the process that would remove this protein need you to be asleep to function properly? To find out, the researchers ’tagged’ the amyloid-beta in volunteers’ brains with a fluorescent chemical so they could follow it from being made to being cleared away.

In general, they found that amyloid-beta levels were low in the morning after a good night’s sleep and increased during the day up until bedtime. It was cleared out of the brain even if the volunteer wasn’t allowed to sleep. This led the researchers to suggest that extra amyloid-beta must be being made in the brains of volunteers who were kept awake.

This study helps us to understand more about how amyloid-beta might be made and removed in the brains of people who don’t have dementia. However, it was a very small study and isn’t able to answer the question of whether a lack of sleep increases a person’s risk of developing dementia. It will be interesting to follow this area of research to learn more about the mysterious function of sleep and its role in brain health.