Sleep helps to evacuate the metabolic waste produced by our brain while awake. This mechanism could prevent neurodegenerative diseases, according to an American study.
- Recovery, metabolism, memory… sleep contributes to different vital functions of the body.
- American researchers have discovered that brain waves help to evacuate waste produced by our cognitive activities during sleep.
- An excess of metabolic waste in the brain can increase the risk of neurodegenerative pathologies.
When we sink into the arms of Morpheus, the brain remains active. Sleep plays a determining role in our health. This state of wakefulness gives us energy, promotes cellular regeneration and even strengthens our memory. According to a recent study published in the journal Nature, Sleeping also helps “cleanse the brain”.
Sleep: an essential function for eliminating metabolic waste
Scientists at the Washington University School of Medicine in St. Louis (United States) have observed that brain waves help flush out metabolic waste present in the brain during the night. However, if this process is hampered, particularly in cases of sleep disorders, debris can accumulate in the brain. Excess waste can increase the risk of neurodegenerative pathologies (Alzheimer’s disease, Parkinson’s disease, etc.). “It is essential for the brain to eliminate metabolic waste that can accumulate and promote the onset of neurodegenerative diseases (…) We knew that sleep is a time when the brain initiates a cleaning process to eliminate accumulated waste and toxins. during wakefulness. But we didn’t know how it happened.”said Jonathan Kipnis, lead author of the study and a neuroscientist at the University of Washington School of Medicine, in a statement.
To understand this mechanism, the study leaders analyzed the brains of sleeping mice. They then noticed that neurons coordinate to produce rhythmic waves, which propel cerebrospinal fluid through dense brain tissue. This liquid which passes through the brain collects toxic waste in its path.
Would improving the brain’s “cleaning” process help us stay healthy?
Secondly, the American team deactivated certain regions of the rodents’ brains so that they no longer created rhythmic waves. In the absence of these waves, cerebrospinal fluid was not able to flow to deactivated areas of the brain, and the waste present could not leave the brain tissue. “If we can improve this cleansing process, it is possible to sleep less and stay healthy. Not everyone gets eight hours of sleep a night, and sleep loss impacts health. D “Other studies have shown that mice genetically programmed to sleep less have healthy brains. Could this be because they remove waste from their brains more efficiently? Could we help people with insomnia by improving the abilities cleansing their brains so they can sleep less?”noted Jonathan Kipnis.
Sleep results in a succession of three to six successive cycles, 60 to 120 minutes each. As scientists have indicated, brain waves change during sleep cycles. Those that are higher and of greater amplitude move fluids with more force. The neurobiologist Li-Feng Jiang-Xie notably compared the process of cleaning the brain to that of washing dishes. “We start, for example, with a broad, slow and rhythmic wiping movement to clean the soluble waste that has splashed on the plate. Then, you decrease the amplitude of the movement and increase the speed of these movements to eliminate the waste particularly sticky foods on the plate. Despite the varying amplitude and rhythm of hand movements, the main goal remains the same: to remove different types of waste from the dishes. Perhaps the brain adapts its method of cleaning according to the type and quantity of waste”he explained.
For researchers, these initial results could pave the way for new strategies and therapies aimed at accelerating the elimination of harmful waste to prevent the risks of neurodegenerative diseases in patients suffering from sleep disorders.
