We all know that a bad night’s sleep can leave us feeling slow, foggy, and irritable the next day. Now, a new study sheds light on why this happens.
Researchers from the University of Camerino in Italy have found that sleep loss damages the fatty insulation surrounding the brain’s nerve cells, which slows down the signals traveling between different parts of the brain.
### The Study Overview
Published in the journal *Proceedings of the National Academy of Sciences*, the study examined both humans and rats to better understand how lack of sleep affects brain function.
The researchers began by analyzing MRI scans from 185 people who reported poor sleep. These scans revealed clear changes in the brain’s white matter—the bundles of nerve fibers responsible for sending signals between various brain regions. This finding confirmed earlier studies linking poor sleep with impaired brain signaling.
### Experiments on Sleep-Deprived Rats
To uncover the cause of these changes, the team conducted experiments on rats that were kept awake for ten days. They measured how long it took for nerve signals to travel between the left and right sides of the brain and discovered that sleep-deprived rats experienced about a 33% delay in signal transmission.
Further investigation of the rats’ brain tissue revealed thinning of the myelin sheaths—the fatty coatings that insulate nerve fibers. These sheaths act like insulation around electrical wires, enabling nerve signals to move quickly and efficiently. Without healthy myelin, communication in the brain becomes slower and less precise.
### The Role of Cholesterol and Oligodendrocytes
The researchers then examined the brain’s fat composition and studied genes related to oligodendrocytes, the cells responsible for producing and maintaining myelin. They found that cholesterol deficiency was the main issue. Cholesterol is essential for creating thick, healthy insulation around nerve fibers, but in sleep-deprived brains, it wasn’t being properly delivered to the myelin sheaths.
### Reversing the Damage
To test potential treatments, the scientists administered cyclodextrin—a compound that helps transport trapped cholesterol back to where it is needed—to the sleep-deprived rats. After treatment, the rats’ myelin sheaths stopped thinning, and the speed of brain signal transmission returned to normal.
Behavioral tests showed that these treated rats performed just as well as rats that had not been deprived of sleep.
### Implications for Human Health
While it is too early to develop treatments for humans based on these findings, the results are promising. If similar effects occur in people, future therapies might focus on restoring cholesterol balance in the brain to prevent damage caused by sleep loss.
The researchers concluded that sleep deprivation affects more than just how tired we feel—it physically alters the brain’s structure, slowing down thinking and reaction times. As the authors noted, “Our findings highlight a possible role of cholesterol regulation in the brain for the behavioral effects of sleep loss.”
This discovery could pave the way for new strategies to protect our brains during periods of insufficient sleep.
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### Additional Health Resources
If you care about brain health, consider exploring the following topics in recent scientific studies:
– The role of **inflammation** in slowing cognitive decline in older adults.
– How **low vitamin D levels** may accelerate cognitive decline.
– The benefits of **common exercises** in protecting against cognitive decline.
– Research on the **MIND diet** and its potential to protect cognitive function and prevent dementia.
For more valuable health information, stay tuned to the latest research updates!
https://knowridge.com/2026/02/sleep-loss-can-cause-silent-brain-damage/