The decrease and quality of neurotransmitters, called “hypocretins”, could be the cause of poorer quality sleep with age.
- Generally, the treatments prescribed to treat insomnia are sleeping pills, but they are not effective for all patients.
- Poor quality and/or lack of sleep can increase the risk of heart attack, depression, diabetes or hypertension.
All doctors recommend it: you must have a regular sleep cycle. In other words, go to bed and get up at the same times every day and sleep, ideally, eight hours a night. These tips are all the more true with age because “more than half of people over 65 complain about the quality of their sleep”, said Luis de Lecea, professor at Stanford University and co-author ofa study published in the journal Science. During their work, the researchers wanted to understand why the quality of sleep decreases with age. They therefore studied, in mice, the brain circuits involved in sleep and the way in which they deteriorate over the years.
Hypocretins, neurotransmitters linked to sleep quality
The researchers focused more specifically on hypocretins. These are neurotransmitters produced by a small part of the neurons in the brain. They are only 50,000. A small amount compared to others that number in the billions. The scientists chose to analyze them more specifically, because previous work had already shown that their degradation could lead to narcolepsy in some patients and a very high need for sleep. In other words, hypocretins would be linked to the quality of sleep. Clearly, the more we have, the better we sleep, and vice versa.
Fewer hypocretins as you age
The scientists conducted their experiments on mice of different age groups: young, from three to five months, and old, that is from eighteen to twenty-two months. The aim was to analyze their hypocretins according to age and to stimulate them in order to see the impact on the quality of their sleep. To stimulate them, they used light. Results: The mice that were between eighteen and twenty-two months old had lost 38% of their hypocretins compared to the young rodents, which implies that stimulation and age decrease the number of these neurotransmitters.
On the other hand, the researchers also observed that the hypocretins that remained in these old mice activated more easily when they were stimulated. An explanation, therefore, for the decrease in the quality of sleep: “Neurons tend to be more active and fire more, and if so, you wake up more frequently.”underlined Luis de Lecea.
Towards more targeted treatments?
For the authors, by better understanding the neurological mechanisms of sleep, this study could make it possible to develop new, more targeted treatments for people who suffer from disorders. Ultimately, therefore, this study could lead to a major breakthrough, especially since current drugs, mainly sleeping pills, “can lead to cognitive difficulties or falls”said Luis de Lecea.
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