As we know, with old age comes the difficulty of having a normal night’s sleep. But why ?
This week the review Science publishes the results of a study conducted by Luis de Lecea, professor of psychiatry and behavioral sciences at Stanford University, United States.
As a preamble, the researcher remarks that “More than half of people over 65 complain regarding the quality of their sleep”. This lack of sleep quality is associated with increased risks of hypertension, cardiac arrest, diabetes, or depression.
The role of hypocretins
With his colleagues, Prof. de Lecea wanted to understand how the brain circuits that are linked to sleep and wakefulness are damaged over the years in mice. And they looked more specifically at hypocretins (or orexins), which are neurotransmitters produced by a tiny fraction of brain neurons, around 50,000 only.
De Lecea is the co-discoverer, in 1998, of these neurotransmitters which have a major role in stabilizing the waking state. Previous studies have already shown that the degradation of these hypocretins can lead to narcolepsy in humans, dogs and mice. Here, scientists selected young and older mice, before using light to simulate specific neurons. Results ? The older mice had lost regarding 38% of hypocretin compared to the younger ones.
Treatments to be developed
It also turned out that the hypocretins still present were triggered more easily; and the teacher says that “Neurons tend to be more active and fire more, and if so, you wake up more frequently”.
Two Australian researchers, who did not take part in this study, commented on the results and according to them, determining the mechanisms behind the loss of sleep might promote the development of more effective treatments than those currently prescribed. . Because they specify, the existing drugs “can lead to cognitive difficulties or falls”.
For his part, Luis de Lecea recalls that clinical trials will be necessary, while arguing that the antiepileptic retigabine is potentially promising.