Nikola Tesla, Donald Trump, and Martha Stewart are just a handful of people who reportedly sleep less than 4 hours a night. It seems that some people can just function on less sleep than most of the dozy eyed population, but is this a matter of steely willed determination or could genetics be at play?
Neurologists from the University of California, San Francisco (UCSF), have found a gene that could have a direct impact on how much someone sleeps.
Reporting in the journal Neuron this week, the findings show that people with the single-letter gene mutation appear to be able to function well on only six hours of sleep without any of the adverse health effects associated with sleep deprivation. Without that one mutation, just six hours of sleep will make you moody, in serious need of a coffee, and even at risk of damaging your health.
"It's remarkable that we know so little about sleep, given that the average person spends a third of their lives doing it," senior author Louis Ptáček, a neurologist at the University of California, San Francisco, said in a statement. "This research is an exciting new frontier that allows us to dissect the complexity of circuits in the brain and the different types of neurons that contribute to sleep and wakefulness."
This is not the first gene the team has linked to how much sleep we need. Back in 2009, the same lab discovered that people who had inherited a particular mutation in a gene called DEC2 averaged only 6.25 hours of sleep per night, while those lacking the mutation averaged 8.06 hours.
This new gene came to light when the researchers found a family of natural short sleepers that didn't have the DEC2 mutation. The researchers screened for genes among people with natural short sleep patterns and found one slight genetic mutation to another gene. The gene in question, ADRB1, appears to affect neurons and their levels of activity in the dorsal pons, a brain region known to control the stages of sleep.
To dig deeper into the puzzle, they then genetically engineered mice to carry the mutated ADRB1 variant. The mice with the mutated ADRB1 neurons slept on average 55 minutes less than regular mice. They also noticed that the mice with the typical ADRB1 neurons in this region were more active during wakefulness and REM (rapid eye movement), the deep stage of sleep associated with dreaming (although the activity was quiet during non-REM). It seems the ADRB1 mutation is affecting the circadian rhythm of the mice.
"Sleep is complicated," Ptáček added. "We don't think there's one gene or one region of the brain that's telling our bodies to sleep or wake. This is only one of many parts."