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 CANT SLEEP, BUT STRESS ISNT 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 ARENT 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 ITS 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, SHAWS 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 DIDNT 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 cant, 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, SHAWS 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 dont sleep very
much. They fall down. Its worth remembering that flies have
six legs, but yet, they still cant 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 wasnt 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 didnt 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 DONT HAVE PROBLEMS THAT ARE AS PRONOUNCED AS WHAT HIS TEAM HAS OBSERVED IN THE FLY. HE SAYS THERE ARE MANY PEOPLE WHO DONT SLEEP VERY MUCH, BUT ONLY THOSE WITH INSOMNIA EXPERIENCE PROBLEMS AS A RESULT.
(act) :12 o/c fundamentally impaired
If youre a human, and youve got insomnia, youre 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 cant. So theyre fundamentally impaired.
HE SAYS BECAUSE THESE ARE FLIES WHO REPRODUCE RAPIDLY, ITS 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. Weve created
a line of flies that they dont lose sleep because theyre
stressed. They lose sleep because they cant 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.
SHAWS TEAM REPORTED ITS FINDINGS IN THE JOURNAL OF NEUROSCIENCE. IM JIM DRYDEN