The work presented in this week's Nature, a scientific journal, built upon their previous work showing that sleep in the fruit fly is eerily similar to mammalian sleep, right down to the level of which genes are activated. Now they have shown that, like mammals, flies will die if they don't sleep.
"The significance of the study is that sleep is an important part of life and that without it you die," said lead project scientist Paul Shaw. "It is so important that it has survived throughout evolution even though it is a costly behavior. While animals sleep, they can't take care of their young, forage for food or engage in any number of other vital biological activities."
In addition to finding that sleep is vitally important in the fly, the investigators identified two genes that play such an important role in sleep function that flies will die after only a few hours of sleep deprivations when these genes are eliminated or reduced. Although the genes were identified in the fruit fly, both genes have counterparts in human. One of the genes has previously been shown to play an important role controlling our internal clock. Among other things, the clock sends out signals that tell us when it is time to wake up and when it is time to go to sleep.
"For many years, most scientists have believed that the sleep and clock mechanisms were independent, although it was widely recognized that they could influence one another," Shaw said. "Our data suggest a much more intimate relationship."
The other gene that they identified has been shown to play an important role in protecting the body against stress. When the investigators applied a stress before they deprived the flies of sleep, the flies survived.
The findings now offer scientists a "hook" to examine more advanced possibilities for sleep related behaviors and afflictions that impact humans. For example, findings may suggest treatments and behavior modifications that eliminate or minimize the impacts of:
- Night shift work
- Sleep disorders
- Jet lag ...
- to name a few
The next research phase of Shaw and his colleagues, Ralph Greenspan and Donald Robinson, at The Neurosciences Institute, is to pin down the mechanisms by which these genes increase and/or protect against the lethal effects of sleep deprivation. Another co-author of the paper, Giulio Tononi, is now at the University of Wisconsin-Madison, Department of Psychiatry.
"The take-home message is that sleep serves a vital biological role, perhaps as important as eating," said Shaw. "Short changing sleep in order to have more time available to accomplish other tasks, is very dangerous and will ultimately fail. In other words, SLEEP!"
The Neurosciences Institute focuses its research on the fundamental principles of functions of the brain, which is the single most complex organ in the known universe. The Institute is a small, privately funded, not-for-profit organization that utilizes an interdisciplinary approach to scientific investigation.
Margo Fox Picou