After examining previous studies of sleep-deprived mice, of which Dr. Veasey conducted many, the researchers found that when the animals were kept awake for just a few hours longer than usual each day, two key areas of the brain were particularly affected: the locus coeruleus, which manages feelings of alertness and arousal, and the hippocampus, which plays an important role in memory formation and learning. Essential in humans for sustaining conscious experience, these regions slowed down animal production of antioxidants, which protect neurons from unstable molecules that are constantly being produced, such as exhaust gases, by functioning cells. When antioxidant levels are low, these molecules can build up and attack the brain from within, breaking down proteins, fats and DNA.
“Wake up in the brain, even under normal conditions, is punished,” said Dr. Fernandez. “But if you are awake for too long, the system becomes overloaded. At some point you can’t pull a dead horse. If you ask your cells to stay active 30 percent longer each day, cells die.”
In the brains of mice, sleep deprivation led to cell death after a few 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 of tau and amyloid proteins, which have been linked to neurodegenerative diseases such as Alzheimer’s and Parkinson’s, in the locus coeruleus and hippocampus.
After an entire year of regular sleep, the mice that had previously been deprived of sleep still suffered from neural damage and brain inflammation. for dr. Veasey and Mr. Zamore suggested that the effects were long lasting and perhaps permanent.
Still, many scientists said the new research shouldn’t be a cause for alarm. “It’s possible that sleep deprivation damages the brains of rats and mice, but that doesn’t mean you should get stressed out because you’re not getting enough sleep,” said Jerome Siegel, a sleep scientist at the University of California, Los Angeles, who is not collaborating on the study. the review.
dr. Siegel noted that neural injury occurs in degrees and that the magnitude of the effect of sleep deprivation on the human brain is still largely unknown. He also expressed concern that excessive concerns about the long-term effects of sleep deprivation could lead people to try to sleep more, unnecessarily, and on medication.
