[Science] DNA mutation lets some people live healthily on only 4 hours’ sleep – AI

By Alice Klein Your genes help determine how much sleep you needDavid Roth/The Image Bank/Getty Do you need a full eight hours of sleep a night or, like Margaret Thatcher famously did, can you get by on four? Researchers have found a gene that dictates how much sleep a person needs by studying a family that gets by on much less than average. Ying-Hui Fu at the University of California, San Francisco and her colleagues analysed the genes of 12 members of a family that sleeps as little as 4.5 hours per night without feeling tired. They found they had a mutation in a gene called ADRB1. Can you beat your genes? Find out from Chris and Xand van Tulleken at New Scientist Live When the team bred rats with the same mutation, these slept about 55 minutes less per day. This correlated with altered activity in a brain region called the dorsal pons that is known to regulate sleep. Advertisement In the dorsal pons of normal rats, ADRB1-expressing brain cells were found to be inactive during most sleep stages, but active when they were awake. In the mutant rats, these cells were even more active during waking hours. The researchers also found they could wake up sleeping rats by artificially activating these ADRB1-expressing brain cells. Extra time Taken together, the results suggest that ADRB1-expressing brain cells promote wakefulness, and that variations in the ADRB1 gene influence how long we can stay awake for each day, says Fu. Her team has previously found that mutations in other genes like DEC2 also make people need to sleep less. These mutations don’t seem to be associated with any negative health consequences. “Most natural short sleepers are very happy about their sleep pattern – they usually fully take advantage of their extra time,” says Fu. Read more: Why dreaming is vital: Unlocking the power of REM sleep So why don’t we all have this ability to function on less sleep? Fu thinks the ADRB1 and DEC2 mutations must have emerged recently in human history and haven’t had time to spread widely yet. “The 8-hour norm has been the standard for a long time, but somehow a few new mutations occurred recently and produced this seemingly advantageous trait,” she says. It may be possible to develop drugs that reduce the amount of sleep we need by mimicking the effects of the ADRB1 mutation, but this is still a long way off, says Fu. Journal reference: Neuron, DOI: http://dx.doi.org/10.1016/j.neuron.2019.07.026 More on these topics: sleep gene brain