"We spend -- or should spend -- a third of our lives sleeping," says Amita Sehgal, PhD, Professor of Neuroscience and an Investigator with the Howard Hughes Medical Institute (HHMI).
"The idea that so much time is spent in sleep is intriguing. Also, sleep deprivation has serious health consequences and impairs cognitive function."
The study has been published in Science.
Fruit flies typically sleep 12 hours a day. In the study, the research team studied 3,500 fruit flies and found mutants that survived on little to no sleep - one to two hours a day or none at all.
The sleepless flies had a mutation of a gene that Sehgal and her team have named Sleepless. They believe the Sleepless gene encodes a protein that affects whether potassium ion channels in the brain stay open or closed.
When the channels are open, the brain is connected and working - the fly is awake. When closed, the channel shuts down and the fly sleeps. The insomniac fruit flies had less of the Sleepless-produced protein.
The lack of sleep didn't come without consequences. The Sleepless fruit flies lived about half as long as fruit flies that did not carry the mutation. They also experience impaired coordination and restlessness in their few hours of sleep.
Sleep is regulated by two processes: circadian and homeostatic. Circadian regulation affects the timing of sleep, and the homeostatic mechanism affects the need for sleep.
The Sleepless gene affects the homeostatic mechanism.