Researchers at the University of Camerino in Italy found that lack of sleep negatively affects the delicate structure that protects nerve cells in the brain, especially the fatty sheath known as myelin, which is essential for ensuring the speed and efficiency of neural signal transmission, as written in Al Arabiya.
The study, published in the scientific journal PNAS, explained that the defect occurs within specialized cells known as oligodendrocytes, which are responsible for regulating the fats and cholesterol required to create myelin that insulates nerve fibers and preserves their proper function.
In the first part of the study, the researchers analyzed MRI scans of 185 healthy volunteers and compared the integrity of the white matter in their brains with the quality of their sleep, based on a standard sleep assessment scale.
How does our brain "rebel" when we deprive it of sleep? A study reveals the facts
The results showed that people who reported poor sleep quality suffered from reduced integrity of the white matter, the area responsible for fast connectivity between different brain regions, which supports the hypothesis that sleep is essential for maintaining a healthy neural structure.
To better understand the biological mechanism, the team conducted experiments on mice that were deprived of sleep for 10 consecutive days. Although the size of the nerve fibers remained constant, the insulating sheath surrounding them became significantly thinner compared to animals with normal sleep.
The researchers also noticed a slowdown of nearly a third in the speed of neural signals, along with poor coordination between different brain regions, which was reflected in the mice’s performance in memory and movement tests, as mentioned in Al Arabiya.
Genetic analysis revealed that lack of sleep led to disruption in the regulation of cholesterol within oligodendrocytes, which weakened their ability to produce myelin with the required efficiency.
In an unusual step, the researchers gave the mice a drug known as cyclodextrin, which helped restore cholesterol transport within the cells, and as a result led to a noticeable improvement in memory and motor performance, confirming that the chemical imbalance was the cause of the damage.
A health challenge
Although most of the findings were based on animal models, the researchers emphasize that these results open a new door to understanding the profound impact of lack of sleep on the human brain, especially in light of increasingly shorter sleep patterns.
The team noted that chronic sleep deprivation has become a public health challenge, due to its link to slower reaction times, increased errors and poor concentration, as well as its previous association with heart disease, depression and dementia.
The researchers conclude that sleep is not just mental rest, but a vital process for repairing the brain and protecting its cells, and warn that ignoring it may leave deeper neurological effects than previously thought.