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Insomniac fruit flies

Researchers at Washington University School of Medicine in St. Louis have created a line of fruit flies that may someday help shed light on the mechanisms that cause insomnia in humans. The flies, which only get a small fraction of the sleep normal flies get, resemble insomniac humans in several ways, and the researchers say this model has clear potential to help them learn more about the causes of insomnia. Someday, it may even help them develop ways to test for or treat those causes in the clinic.

BEDTIME CAN BE VERY STRESSFUL FOR PEOPLE WHO CAN’T SLEEP, BUT STRESS ISN’T THE ONLY THING THAT CAUSES INSOMNIA. LIKE MANY DISORDERS, THE PROBLEM INVOLVES BOTH GENETIC AND ENVIRONMENTAL FACTORS. AND AS JIM DRYDEN REPORTS, WASHINGTON UNIVERSITY SCIENTISTS HAVE DEVELOPED A LINE OF FRUIT FLIES THAT MAY BE ABLE TO SHED SOME LIGHT ON THE MECHANISMS THAT CAUSE INSOMNIA IN HUMANS…

ALL OF US HAVE TROUBLE SLEEPING FROM TIME TO TIME. A BIG TEST IN THE MORNING OR AN IMPORTANT BUSINESS MEETING CAN LEAVE YOU TOSSING AND TURNING. SO CAN A FIGHT WITH YOUR SIGNIFICANT OTHER. BUT THOSE TYPES OF SLEEPLESS NIGHTS AREN’T THE SAME THING AS INSOMNIA. WASHINGTON UNIVERSITY NEUROBIOLOGIST PAUL SHAW SAYS MOST OF US WILL EXPERIENCE A FEW SLEEPLESS NIGHTS EVERY SO OFTEN. AND SOME PEOPLE ACTUALLY NEED LESS SLEEP THAN OTHERS. BUT FOR MANY, LACK OF SLEEP IS A BIG PROBLEM. THOSE ARE THE PEOPLE WHO SUFFER FROM CHRONIC INSOMNIA. SHAW SAYS IT’S A VERY TOUGH DISEASE TO STUDY IN ANIMALS, BUT HIS TEAM OF RESEARCHERS NOW HAS FOUND A GOOD MODEL ORGANISM: THE FRUIT FLY. IN THESE DAYS OF GENETIC ENGINEERING, SHAW’S BRED THESE FLIES TO HAVE INSOMNIA IN THE WAY THAT BOTANISTS IN THE MIDDLE AGES MIGHT HAVE MADE A NEW TYPE OF ROSE, OR DOG BREEDERS MIGHT HAVE CREATED A CHIHUAHUA. FIRST, THEY OBSERVED THE BEHAVIOR OF THE FLIES. THEN THEY MATED THOSE THAT DIDN’T SLEEP MUCH WITH OTHER FLIES THAT ALSO TENDED TO SLEEP LESS.

(act) :17 o/c messed up

They had difficulty going to sleep. They had difficulty

staying asleep. They looked hyperactive. Just looking at a

wild-type population of flies, some flies sleep great. Some flies

just can’t, and we thought, “Well, God, what if we take all of

these flies, and we breed them together over successive generations?

Can we get a fly that is really messed up?”

EVENTUALLY, SHAW’S TEAM CREATED A LINE OF FRUIT FLIES THAT SLEEPS FOR ONLY ABOUT AN HOUR PER DAY. AND HE SAYS IT TURNS OUT THAT THE FLIES HAVE MANY OF THE SAME PROBLEMS AS HUMANS WITH INSOMNIA.

(act) :36 o/c them anyway

We have these insomnia-like flies that they don’t sleep very

much. They fall down. It’s worth remembering that flies have

six legs, but yet, they still can’t maintain their balance.

And that seemed strange to us. We thought that maybe these

flies had some degenerative problem, and so we sent our flies

to experts in the field of degeneration to see if they could

identify problems with their brain. And they looked, and they

came back with a clean bill of health, no serious problems.

And it wasn’t until a couple of months, maybe a year, later

that I was reading a review article, and I found a reference

showing that human insomniacs also have difficulty maintaining

their balance. So here we created a line of insomniac flies.

We didn’t necessarily know all of the features we should be

looking for, and we found them anyway.

THAT SUGGESTS TO SHAW THAT HIS TEAM IS ON THE RIGHT TRACK. HE SAYS HUMANS WITH INSOMNIA DON’T HAVE PROBLEMS THAT ARE AS PRONOUNCED AS WHAT HIS TEAM HAS OBSERVED IN THE FLY. HE SAYS THERE ARE MANY PEOPLE WHO DON’T SLEEP VERY MUCH, BUT ONLY THOSE WITH INSOMNIA EXPERIENCE PROBLEMS AS A RESULT.

(act) :12 o/c fundamentally impaired

If you’re a human, and you’ve got insomnia, you’re cognitively

impaired on certain tasks. And so we have an assay in the fly

that measures short-term memory. We ask, “Can our flies learn

this task?” and they can’t. So they’re fundamentally impaired.

HE SAYS BECAUSE THESE ARE FLIES WHO REPRODUCE RAPIDLY, IT’S POSSIBLE TO QUICKLY LEARN ABOUT UNDERLYING GENETIC MECHANISMS THAT MAY BE CONTRIBUTING TO SLEEP PROBLEMS.

(act) :19 o/c altered state

Stress disrupts sleep. We know that to be true, but insomnia

is not solely a case of people being stressed. We’ve created

a line of flies that they don’t lose sleep because they’re

stressed. They lose sleep because they can’t sleep. It more

closely resembles what we see in humans, as opposed to some

other animal studies where you have to artificially induce

some kind of altered state.

SHAW’S TEAM REPORTED ITS FINDINGS IN THE JOURNAL OF NEUROSCIENCE. I’M JIM DRYDEN…

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