Researchers from Northwestern University, who were inspired by a fruit fly, discovered what exactly controls our ability to wake up and fall asleep.
The idea to research the mechanisms of sleep originated 15 years ago when the attention of Dr. Ravi Allada’s attention was caught by a mutated fruit fly.
The biological clock which aids in sleep and waking up works similar to a light switch. Allada and his team of researchers uncovered that high sodium channel activity that occurs during the day turns cells on, which wakes up animals. Additionally high potassium channel activity turns cells off at night, which prompts sleep. This mechanism of sleep was observed in both flies and mice.
Allada said, “This suggests the underlying mechanism controlling our sleep-wake cycle is ancient. This oscillation mechanism appears to be conserved across several hundred million years of evolution. And if it’s in the mouse, it is likely in humans, too.”
A better understanding of how we sleep has the potential to create targeted treatments for sleep problems associated with jet-lag, shift-work and other clock-related sleep problems. It may even be possible in the future to reset a person’s biological clock to fit given situations.
The sleep mechanism is referred to as a “bicycle” mechanism. Essentially, two pedals continue to go up and down over the course of 24 hours, transiting important information through neurons. The two pedals are sodium and potassium.
Lead author, Matthieu Flourakis, said, “What is amazing is finding the same mechanism for sleep-wake cycle control in an insect and a mammal. Mice are nocturnal and flies are diurnal, or active during the day, but their sleep-wake cycles are controlled in the same way.”
Flourakis was interested in whether or not the activity found in fruit flies’ circadian neurons changed with the new day. With the assistance of the research team he uncovered strong rhythms: Neurons fired more during the day and less at night.
By only studying flies at first, both Flourakis and Allada wanted to test their theory on animals closer to humans, prompting the research to move on to mice. They studied a region of a mouse’s brain which controls its circadian rhythm and found the same mechanisms present as fond in the fruit flies.
Allada concluded, “Our starting point for this research was mutant flies missing a sodium channel, who walked in a halting manner and had poor circadian rhythms. We have more questions about what’s regulating this sleep-wake pathway, so there is more work to be done.”
The study was published in the journal Cell.