Sleep Scientists Are Keeping Fruit Flies Up All Night To Study Insomnia In Humans

Alap Naik Desai

Insomnia is a chronic condition that affects millions, yet medical science is still far from unraveling its mysteries. However, scientists are hoping to make a breakthrough soon if their fruit flies offer some insight.

Researchers at Washington University School of Medicine in St. Louis have created a line of fruit flies that they hope will someday offer newer insights in the mechanisms that cause insomnia in humans. Interestingly, the flies, which only get a small fraction of the sleep as compared to normal flies, significantly resemble insomniac humans.

Explaining the experiment, senior author Paul Shaw, Ph.D. said, "Insomnia is a common and debilitating disorder that results in substantial impairments in a person's quality of life, reduces productivity and increases the risk for psychiatric illness. We think this model has clear potential to help us learn more about the causes of insomnia and someday develop ways to test for or treat them in the clinic."

How will scientists understand insomnia in humans from keeping fruit flies awake? Shaw and his team have successfully identified a biomarker that is very common in both flies as well as humans. His experiment was the first to conclusively prove that fruit flies enter a state of inactivity that closely resembles sleep. Moreover, the researchers recurrently demonstrated that the flies have periods of inactivity where greater stimulation is required to rouse them.

This might sound quite relatable, since humans too, when deprived of sleep one day, will try to make up for it by sleeping more the next. This typical phenomenon is referred to as increased sleep drive or sleep debt.

It was a little difficult for Shaw to pinpoint flies who suffered from insomnia. As he studied the healthy flies, Shaw noticed that a few flies naturally slept less than others. He decided to take flies with insomnia-like characteristics and breed them to amplify those qualities. Needless to say, just like humans, the flies he bred had difficulty falling asleep in normal circumstances, and their sleep was often interrupted or fragmented.

Since fruit flies live for a fortnight or so, Shaw was able to amplify the insomnia by selective breeding. Choosing the flies for breeding was quite easy. If researchers turned on a light at night, insomniac flies woke and stayed up the rest of the night, while the healthy flies went back to sleep. The flies that stayed up were added to the breeding pool.

The experiments have shown that those flies who were severely affected with insomnia regularly stumbled, had poorer appetite, were slow learners, and gained more fat. While these are certainly negative traits born out of insomnia, intentional sleep-deprivation also developed resistance to the adverse effects of lack of adequate sleep.

Researchers are speculating that some genes, altered by insomnia and sleep deprivation, may simultaneously contribute to both detrimental and temporarily advantageous effects, reported Sleep Review. Careful manipulation of the same could even result in ensuring humans perform better, despite sleeping less.

[Image Credit | James Gorman]