Lost sleep can leave dangerous toxins hiding in the brain

Sleep can improve brain ability to eliminate harmful waste. A mediocre or disturbed sleep could increase the risk of dementia.

The brain has its own system to remove waste, known as the glymphatic system, which becomes more active during sleep.

When sleep is disturbed, this cleaning process can be altered, slowing the elimination of toxins and other brain waste. Researchers suggest that the accumulation of such toxins due to inadequate sleep could contribute to a higher risk of dementia.

Uncertainty remains on how the glymphatic system works exactly in humans, because a large part of the current evidence comes from mouse studies. However, these results raise the possibility that better sleep could improve the clearance of harmful substances in the brain and therefore a lower risk of dementia.

Here is what researchers currently understand this field of development in development.

Why waste is important

All body cells generate waste. Outside the brain, the lymphatic system eliminates this material by carrying it spaces between cells in the bloodstream through a network of vessels.

However, the brain does not have its own lymphatic vessels. Until about 12 years ago, scientists did not know how the brain had managed its waste. This has changed with the discovery of the glymphatic system, which was described as a mechanism that “eliminates” brain toxins.

The cerebrospinal fluid, which surrounds both the brain and the spinal cord, plays a central role in this process. The fluid flows around the blood vessels in the brain, then moves in the spaces between the cells of the brain, where it collects waste before flowing through large veins.

Studies on mice then demonstrated that the glymphatic system becomes the most active during sleep, with the elimination of waste significantly increased at that time.

One of the substances eliminated through this system is the amyloid beta (Aβ) protein. When Aβ accumulates in the brain, it can form plates. In addition to tangles of another protein, tau, found in neurons, these plates are key characteristics of Alzheimer’s disease, the most common form of dementia.

In humans and mice, studies have shown that the levels of Aβ detected in cerebrospinal fluid increases when they are awake and quickly fall during sleep.

But more recently, another study (in mouse) has shown roughly the opposite – suggesting that the glymphatic system is more active during the day. Researchers debate what could explain the results.

We therefore still have a long way to go before we can say exactly how the glymphatic system works – in mice or humans – to eliminate the brain from toxins which could otherwise increase the risk of dementia.

Does this also happen in humans?

We know that sleeping is good for us, especially our brain health. We are all aware of the short -term effects of sleep deprivation on the ability of our brain to work, and we know that sleep helps improve memory.

In an experience, a single night of complete sleep deprivation in healthy adults has increased the amount of Aβ in the hippocampus, an area of ​​the brain involved in Alzheimer’s disease. This suggests that sleep can influence the clearance of the AU? Human brain, supporting the idea that the human glymphatic system is more active while we sleep.

This also raises the question of whether good sleep could lead to better clearance of toxins such as Aβ of the brain, and therefore be a potential target to prevent dementia.

And sleep apnea or insomnia?

What is less clear is what disturbed long -term sleep, for example if someone suffers from a sleep disorder, means the capacity of the body to eliminate Aβ from the brain.

Sleep apnea is a common sleep disorder when someone’s breathing stops several times during sleep. This can lead to a deprivation of chronic sleep (long -term) and a reduction in oxygen in the blood. Both can be involved in the accumulation of toxins in the brain.

Sleep apnea was also linked to an increased risk of dementia. And we now know that after people are treated for sleep apnea, more Aβ is eliminated from the brain.

Insomnia is when someone has trouble falling asleep and / or stay asleep. When this happens in the long term, there is also an increased risk of dementia. However, we do not know the effect of the treatment of insomnia on toxins associated with dementia.

Again, it is still too early to say it with certainty that the treatment of a sleep disorder reduces your risk of dementia due to the reduced levels of toxins in the brain.

So where does that leave us?

Collectively, these studies suggest that enough good quality sleep are important for a healthy brain, and in particular to clean the toxins associated with the dementia of the brain.

But we still don’t know if treatment Sleeping disorder or sleep improvement more widely affects the brain’s ability to eliminate toxins and if it reduces the risk of dementia. They are researchers from the region, which we are actively working.

For example, we are studying the concentration of Aβ and tau measured in the blood through the 24 -hour sleep -in -sleep cycle in people with sleep apnea, on and out of treatment, to better understand how sleep apnea affects brain cleaning.

Researchers also examine the processing potential of insomnia with a class of drugs called orexin receptor antagonists to see if it affects the brain’s AUβ clearance.

If you are worried

It is an emerging field and we do not yet have all the answers on the link between disturbed sleep and dementia, or if better sleep can increase the glymphatic system and therefore prevent cognitive decline.

So if you are concerned about your sleep or your cognition, please consult your doctor.

Adapted from an article initially published in the conversation.

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