"Feed a cold, starve a fever," the saying goes. However, fruit fly experiments suggest that sleep can be a better remedy.
A microbial-controlling protein helps to control how much and how deeply fruit flies sleep, researchers report in Science of February 1 Science . That's proof that sleep speeds recovery, they conclude.
"We finally have a clear link between drowsiness and infection control," says Caltech sleep researcher Grigorios Oikonomou, who was not involved in the work. Such a link was suggested, but never formally demonstrated, says Oikonomou, who authored a commentary to the study in the same issue of Science
. Researchers in the laboratory of Amita Sehgal at the Perelman School of the University of Pennsylvania of Medicine made the discovery in search of genes that control sleep. Her team was looking for proteins that would cause more fruit flies in overproduction Drosophila melanogaster . After combing over 8,000 overproduced proteins, researchers found only one that made flies sleep.
Flies with an abundance of this protein, produced from the nemuri gene, slept longer during the day, sleeping longer and deeper at night. Strong surveys of a device called the Hammer aroused only about 1
The Sehgal team discovered that Nemuri resembles fish proteins known as antimicrobial peptides, short proteins or pieces of protein that can kill microbes. In tests of the Nemuri effect on two types of bacteria, the protein killed the bacteria in laboratory bowls and helped bacteria-infected fruit flies survive longer if overproduced.
The likelihood of the protein, not its antimicrobial action, could be fought infection flies made more Nemuri, not only when they were ill, but also when sleep was inferior and other types of stress were exposed. "Sleep helps fight these challenges," says Sehgal. Nemuri may not be as important for daily sleep except for the nighttime sleep
A dual role in killing bacteria and inducing sleep is new for antimicrobial peptides, says Robert Hancock, a microbiologist and immunologist at the University of British Columbia in Vancouver. "But I'm not shocked," he says, "because peptides do so many things."
Antimicrobial peptides are generally not that good at killing microbes in animals, says Hancock. Instead, the peptides help to regulate the immune system for a variety of tasks. However, it is possible that mammals, including humans – with more than 100 antimicrobial peptide genes – have antimicrobial peptides that induce sleep during illness.
"Bringing an animal to fall asleep and concentrate all its resources on fighting infections is useful to host the defense," says Hancock. Or as an Irish saying goes, "A good laugh and a long sleep are the best healings in the doctor's book."