Thoughts in a Haystack

According to Science, researchers have found a protein in flies and human saliva that seems to signal how sleepy an individual is. This can have obvious application to making sure that certain professionals and crucial workers are really fit to do their jobs, assuming an easy test can be devised. Airline pilots, medical interns, long-haul truck drivers and the like could possibly be monitored to insure they are not too fatigued to properly do their work.

The first tantalizing clue came last year when neurobiologist Paul Shaw and his team at Washington University in St. Louis, Missouri, found that when fruit flies get sleepy, they make more amylase--an enzyme found in human saliva that breaks down starches. The protein did not appear to control sleep, says Shaw, but he wondered if it could serve as "a readout of being sleepy." ...

Flies take short naps during the day, and researchers can judge how tired the insects are by observing how much extra naptime they need. After a several hours spent wired with caffeine, flies deprived of sleep for 9 to 12 hours increased their nap length 2 to 7 fold. In addition, their amylase levels were five times those seen in flies not given caffeine. In another experiment, the team marked the amylase with a bioluminescent protein. Flies kept awake using caffeine glowed brighter than those allowed to sleep on their own schedule, the team reports online this week in Proceedings of the National Academy of Sciences.

The findings appear to hold true in people as well. When the team deprived nine volunteers of sleep for 28 hours, all showed either higher levels of amylase protein or amylase messenger RNA (an indicator of gene activity) in their saliva than they did after a normal night's sleep.

Although more study in humans is needed, "such a finding could eventually lead to a practical assay for sleepiness to identify people at risk for sleepiness-related mishaps," says James Walsh, a psychologist at Saint Louis University in Missouri ...

Link - Posted by John Pieret @ 5:51 PM