Your Amazing Brain!

Maiken Nedergaard is a charming Danish neuroscientist who has changed sleep science forever — and she has helped explain why Alzheimer’s disease is connected to poor sleep! 

Your brain’s ‘glymphatic system’

In 2013, Dr. Nedergaard revealed her discovery of the ‘glymphatic system’ — your brain’s amazing system to cleanse itself during sleep. 

Every night, during deepest sleep, the ‘astroglial’ cells of your brain actively shrink in size and arrange to form special channels that open wide. This lets the cerebrospinal fluid that bathes your brain flow freely through these channels, flushing away all the waste matter that collected earlier in the day while your mind was awake.

Neuroscientist Matthew Walker has called this the brain’s “nighttime power cleanse”. Every night your brain is busy like this, actively cleansing itself while you're sleeping. 

For some reason, this process happens during sleep. It seems the brain cannot effectively eliminate waste during wakefulness. The glymphatic network and its nighttime 'power cleanse' are most powerful during deepest sleep.

The cost of wakefulness?

This self-cleansing process is essential because your brain works so hard to give you wakefulness during the day.  

Wakefulness requires countless chemical processes that happen in your brain every second — chemical processes that produce waste by-products such as ‘amyloid-beta’. 

Amyloid-beta is a toxic substance that can harm nerve cells. Significantly, it is most commonly found in the brains of people who have Alzheimer’s disease. Toxic by-products like amyloid-beta need to be eliminated before they accumulate in the brain — that’s why your brain requires its nightly ‘power-cleanse’!

Alzheimer’s disease

For some years, research has shown that cognitive decline & Alzheimer’s disease are somehow connected to habitual poor sleep. 

Now, with Dr. Nedergaard’s discovery of the glymphatic system, we begin to understand why research shows that people who sleep 7-8 hours nightly are less likely to develop Alzheimer’s disease. 

When we get plenty of sleep (especially deep sleep) the brain’s glymphatic system has a chance to flush away brain waste. Harmful toxins like amyloid-beta are less likely to accumulate. 

It now seems likely that some people are predisposed to Alzheimer’s disease because they lack adequate sleep.

And here's a final comment from Dr. Nedergaard

Dr. Nedergaard’s recent study of Alzheimer's disease was published in the influential scientific journal, 'Science'.  You won’t be surprised to read how she praises "a good night's sleep".   [see excerpt below]

Fundamentally, these studies have served to highlight the benefits of a good night’s sleep. 

Little can replace the rejuvenating feeling of a good night’s sleep. Our mood and affect, ability to attend, focus and problem solve, are all directly linked to how well we sleep.

Indeed, the benefits of sleep are cumulative; they are not restricted to the morning hours, or even to a given day.

Good sleepers live longer, weigh less, have a reduced incidence of psychiatric disorders, and remain cognitively intact longer. 

Glymphatic failure as a final common pathway to dementia. 

Maiken Nedergaard et al. Science 2020 Oct 02 

To your natural happiness! 

Lucinda

Reference

Glymphatic failure as a final common pathway to dementia. 

Maiken Nedergaard et al. Science 2020 Oct 02