We all know that a bad night’s sleep can make us feel slow, foggy, and irritable the next day. Now, a new study explains why.
According to researchers from the University of Camerino in Italy, sleep loss damages the fatty insulation around the brain’s nerve cells, which slows down the signals that travel between different parts of the brain.
The study, published in the journal Proceedings of the National Academy of Sciences, looked at both people and rats to better understand how lack of sleep affects the brain. The scientists started by reviewing MRI scans from 185 people who said they didn’t sleep well.
These scans showed clear changes in the white matter of the brain, which is made up of bundles of nerve fibers that send signals between different areas. These results confirmed earlier studies that found a connection between poor sleep and problems with brain signal…
To figure out the cause, the team ran tests on rats that were kept from sleeping for ten days. The scientists measured how long it took for nerve signals to travel between the left and right sides of the brain.
They found that sleep-deprived rats had about a 33% delay in signal transmission. Something was clearly slowing down the brain’s communication.
When the researchers looked closely at the rats’ brain tissue, they found that the myelin sheaths—the fatty coatings that insulate nerve fibers—had become thinner. These sheaths are like the insulation around electrical wires.
They help nerve signals move quickly and efficiently. Without them, communication in the brain becomes slower and less accurate.
To understand why this was happening, the team examined the fat makeup of the brain and looked at the genes related to a type of cell called oligodendrocytes. These cells are responsible for making and maintaining myelin.
They discovered that the main problem was a lack of cholesterol, which is essential for forming thick, healthy insulation around nerve fibers. The cholesterol wasn’t being delivered properly to the myelin sheaths.
To test if they could fix the problem, the scientists gave the rats a substance called cyclodextrin. This compound helps move trapped cholesterol back into the areas where it is needed.
After treatment, the rats’ myelin sheaths stopped thinning, and their brain signal speeds returned to normal. In behavior tests, the treated rats performed just as well as those that had not been sleep-deprived.
While it is too soon to start talking about new treatments for humans, the results are promising. If the same effects are found in people, future therapies might focus on restoring cholesterol balance in the brain to prevent the damage caused by sleep loss.
The researchers concluded that sleep deprivation affects more than just how tired we feel. It changes the physical structure of our brains in ways that slow down thinking and reaction time.
“Our findings highlight a possible role of cholesterol regulation in the brain for the behavioral effects of sleep loss,” the study authors wrote. This could lead to new ways to protect our brains when we don’t get enough sleep.
If you care about brain health, please read studies about inflammation that may actually slow down cognitive decline in older people, and low vitamin D may speed up cognitive decline.
For more health information, please see recent studies about common exercises that could protect against cognitive decline, and results showing that this MIND diet may protect your cognitive function, prevent dementia.
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