Scientists have pinpointed a gene mutation in fruit flies that makes them experience the fly version of insomnia.
The findings could help in the search for effective treatments for people with insomnia or who have trouble sleeping due to shift work.
"We know that the timing of sleep is regulated by the body's internal biological clock, but just how this occurs has been a mystery," study researcher Dr. Mark N. Wu, M.D., Ph.D., an assistant professor of neurology, medicine, genetic medicine and neuroscience at the Johns Hopkins University School of Medicine, said in a statement. "We have now found the first protein ever identified that translates timing information from the body's circadian clock and uses it to regulate sleep."
In the Neuron study, researchers identified a gene, called the "Wide Awake" gene, which seems to play a role in delivering the message that "it's time to sleep" from the circadian clock to the brain.
In fruit flies that had trouble falling asleep, researchers found that mutations in this gene affected the ability of the brain's clock neurons (which control arousal) to receive signals from a neurotransmitter called GABA. This, in turn, kept the arousal circuits from quieting down, thereby impairing the flies' ability to fall asleep.
Researchers noted that the Wide Awake gene is also present in humans, chickens, mice and even worms. They noted that when they studied the gene in mice, the gene was expressed in high concentrations in the "master clock" region, called the suprachiasmatic nucleus. "Because we found the protein in a location where it likely plays a role in circadian rhythms and sleep, we are encouraged that this protein may do the same thing in mice and people," Wu said in the statement.