Consequences of a lack of sleep

By reviewing past studies of sleep-deprived mice, many of which Dr. Vesey, the researchers found that when the animals were awake just a couple of hours more than usual each day, two key parts of the brain were noticeably affected: the locus coeruleus, which governs feelings of alertness and arousal, and the hippocampus. , which plays an important role in memory formation and learning. These areas, which in humans play a central role in maintaining conscious experience, slow down the production of antioxidants in animals, which protect neurons from unstable molecules that are constantly produced, like exhaust gases, by functioning cells. When antioxidant levels are low, these molecules can build up and attack the brain from within, destroying proteins, fats, and DNA.

“Waking the brain, even under normal circumstances, comes with penalties,” the doctor says. Fernandez said. “But when you stay awake for too long, the system overloads. At some point, you can’t beat a dead horse. If you ask your cells to stay active 30 percent more each day, the cells die.”

In the brains of mice, sleep deprivation resulted in cell death after several days of sleep restriction — a much lower threshold for brain damage than previously thought. It also caused inflammation in the prefrontal cortex and increased levels tau as well as amyloid proteins that are associated with neurodegenerative diseases such as Alzheimer’s and Parkinson’s in the locus coeruleus and the hippocampus.

After a full year of regular sleep, the previously sleep-deprived mice still suffered from nervous system damage and brain inflammation. To Dr. Veasey and Mr. Zamora, this suggests that the effects were long lasting and possibly permanent.

However, many scientists said the new study should not cause panic. “It’s possible that sleep deprivation damages the brains of rats and mice, but that doesn’t mean you should be stressed out about not getting enough sleep,” said Jerome Siegel, a sleep researcher at the University of California, Los Angeles. to the review.

Dr. Siegel noted that nerve damage manifests itself to varying degrees, and that the extent to which sleep deprivation affects the human brain is still largely unknown. He also expressed concern that over-anxiety about the long-term effects of sleep deprivation could lead people to try to sleep more unnecessarily and with the help of medication.