Human evolution: sleep length genetically controlled (Introduction)

by David Turell , Thursday, June 24, 2021, 19:21 (1248 days ago) @ David Turell

Study shown in mice and in this family:

https://edition.cnn.com/2021/06/22/health/short-sleep-gene-wellness-scn/index.html?utm_...

"For as long as he can remember, Brad Johnson knew he was different.

"'I've never been normal when it came to sleep," Brad told CNN. "Other people, even some of my siblings, slept eight, nine, 10 hours a night. I just couldn't do it, it was physically impossible. If you paid me a million dollars to sleep eight hours tonight, I couldn't."
It didn't seem to matter what time he went to bed, how little sleep he'd had or how tired he was from the day's activities, both as a child and now, at age 64, Brad said.
'I'd get five hours and be done. Up, ready to go," he said. "I wasn't groggy, I wasn't tired, just ready to roll and go."

***

"Brad wasn't alone. In his large Mormon family of eight kids, his two older brothers Rand and Paul also woke early and suffered no ill effects. In fact, the boys were amazingly productive, driven to wake and immediately tackle life with gusto and high spirits.

"In the dark, wee hours of those mornings the boys practiced basketball, did homework and hobbies and read everything they could get their hands on.

"'Everyone in our family loves to read," Brad said. "We are voracious, voracious readers."

***

"The birth of the idea that people might sleep for only five hours and bypass the ill effects of sleep deprivation was sheer "serendipity," said neurology professor Ying-Hui Fu, who conducts sleep gene research at the Weill Institute for Neurosciences at the University of California, San Francisco.

***

"The hunt was on for more people -- like the Johnsons -- who fit that pattern. By 2009, the team published their first finding: There was a mutation in the gene DEC2 which caused short sleepers to stay awake longer. Since then, the team has discovered two more genes -- an ADRB1 mutation and a NPSR1 mutation -- which alter neurotransmitters in the human brain to create short sleep.

"During each of these studies, the team bred mice with the same genetic mutations to test the gene's function. The results: Genetically-altered mice also slept for fewer hours, with no negative health effects.

***

"Sleep is the time when the body consolidates memories, and cleanses the brain of neurotoxins. Without the necessary REM and deep wave sleep that a full eight hours of slumber brings, most people struggle with memory recall, Fu said.

"'Yet mice, and presumably humans with the short sleep gene mutation, remember quite well on little sleep, whereas most people won't remember much of anything if you deprive them of sleep," she said."

Comment: Not a surprising finding. I reviewed the mouse study paper and it added nothing to this story.