Danish researchers reveal that sleep is far from linear. But don’t worry, it would be good for memory.
There are micro-awakenings that are more beneficial than others. While some are the result of a sleep disorder that needs to be treated, others are perfectly normal. Uninterrupted sleep simply does not exist, according to the results of a study published in the scientific journal Nature. “We wake up more than 100 times a night and that’s perfectly normal,” says research author Celia Kjærby.
To arrive at this observation, scientists from the University of Copenhagen, in Denmark, studied the sleep of mice using sensors and microscopic optical fibers, a model transposable to humans. They noted more than 100 awakenings per night, but in such a short time that the sleeping person would not realize it. “You could say that short awakenings reset the brain so that it’s ready to store memory when it’s time to fall back into sleep,” explains Maiken Nedergaard, the lead author of the research.
Noradrenaline at the origin of micro-awakenings
In detail, it would be norepinephrine, a neurotransmitter, which would be at the origin of micro-awakenings. The more its level varies during sleep, the better the memory would be afterwards. The proof is with mice. “They had less difficulty remembering things they had learned the day before. This suggests that the dynamics of norepinephrine reinforce the sleep processes that affect our memory”, concludes Celia Kjærby.
But if you feel tired in the morning, drowsy during the day, have difficulty concentrating or memorizing persistently over time, a consultation with a doctor is essential. You may suffer from micro-awakenings which abnormally affect your sleep. In France, one in three adults is affected by a sleep disorder such as insomnia, sleep apnea or even restless leg syndrome.
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