Restful nights of only 4 to 6 hours? A gene explaining this ability to sleep less has been identified by American researchers.
Having a short but restorative sleep is a lot of time gained in a life of which “normal” humans use a third of the time to…sleep! By studying a family whose members need less sleep than average, American researchers have just identified a gene that explains this particularity.
“This is an exciting new frontier that allows us to dissect the complexity of circuitry in the brain and the different types of neurons that contribute to sleep and wakefulness,” said Louis Ptacek, a neurologist at the University of California at San Francisco. Francisco, lead author of this study published in the journal Neuron.
A new and very rare variant of the ADRB1 gene
The family members whose study led to the identification of this gene live completely normal lives with only six hours of sleep per night, two hours less than the average. The researchers identified a new and very rare variant of the ADRB1 gene in them.
The first step in deciphering the role of this gene variant was studying its protein in a test tube. “We found that the mutant version of the protein is much less stable, which modifies the function of the receptor and suggests that this could have functional consequences on the brain”, specifies Louis Ptacek.
The part of the brain that manages subconscious activities
His team then conducted several experiments on mice carrying a mutated version of this gene. They found that these animals slept an average of 55 minutes less than “regular” mice. Further analysis showed that the gene was expressed at high levels in a part of the brainstem involved in subconscious activities such as breathing, eye movements and sleep.
Additionally, she found that normal ADRB1 neurons in this brain region were more active not only during wakefulness but also during REM sleep, and that mutant neurons were even more active than normal neurons, likely contributing to sleep time. short.
Control sleep and wakefulness
However, this work on mice is not completely conclusive for humans. These animals indeed have very different sleeping habits by sleeping according to a fragmented configuration from those of humans who sleep during a single continuous period.
Ptacek and his team plan to study the function of the ADRB1 protein in other parts of the brain and look for other gene families that may be important: “We don’t think there is a single gene or region of the brain that tells our body to sleep or wake up is just one part of it,” he says.
This work could ultimately lead to the development of new drugs to control sleep and wakefulness.
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