Sleep Breaks Down Toxins in the Brain

During sleep, Sleep Breaks Down Toxins in the Brain, which are responsible for Alzheimer's disease and other neurological disorders. Researchers have discovered a waste management system that operates during sleep, which helps clear out the brain of harmful molecules and other metabolic byproducts. The wastes are removed by convective motion of fluid inside the brain. This system may also have a role in neurodegeneration following traumatic brain injury. It is unknown how the system works, but it is believed to involve a series of channels in the membranes of glial cells, the non-neuronal cells that control the flow of fluid through the glymphatic system.

The brain may clean itself

Previously, scientists knew that sleep did not decrease energy consumption in the brain, but they did not know how the brain used this energy. Now, researchers have found that the amount of beta amyloid protein in the brain decreases during sleep, suggesting that the brain may clean itself. Beta amyloid is a harmful protein that forms sticky plaques in the brain of Alzheimer's patients. Research suggests that people who have high levels of the protein have poor sleep quality, which increases their risk for developing the disorder.

One way the brain clears toxins during sleep is by allowing a fluid to wash in and out of the brain. The cerebrospinal fluid (CSF) transports a variety of waste products from the brain, including beta amyloid, into the bloodstream. During sleep, the fluid's volume increases dramatically, which helps flush the waste out of the brain.

The glymphatic system

A series of tubes that carries CSF and mixes fresh fluid with waste - is active during sleep, according to the study. Brain cells shrink during sleep, creating more space between them, allowing the CSF to freely wash through the tissue. Nedergaard's team was able to demonstrate that the glial channels that carry CSF are controlled by glial cells. When the channels were blocked, the flow of CSF was inhibited.

Nedergaard and his colleagues were able to discover a previously unknown cleaning system in the brains of sleeping mice. This discovery was published last summer in Science Translational Medicine. They compared the cleaning process to opening and closing a faucet. Their hypothesis was that the brain would not be able to do both at the same time.

Nedergaard's team was funded by the National Institute of Neurological Disorders and Strokes. He and his team were able to measure how quickly beta amyloid protein disappeared in the brains of mice during sleep. They found that b amyloid proteins were cleared away from the brains twice as fast when the mice were asleep. These findings could help researchers understand the processes behind Alzheimer's and other neurological diseases.

Sleep is essential to the healthy functioning of the brain. Not only does it allow the brain to rest, but it also has a restorative effect on cognition and memory consolidation. While studies have shown that the brain can be damaged by too much sleep, the new research indicates that sleep may benefit the brain by clearing out toxins and metabolic byproducts.