"This tests the flies' mental capacity in two ways: First, they've got to remember that the lighted vial is the one that has quinine in it, and then they've got to suppress their natural instinct to fly toward the light," says Seugnet.
Flies allowed normal sleep learned to avoid the lighted vial, but sleep-deprived flies did not.
A brain messenger known as dopamine is linked to some of the mental capabilities harmed by sleep loss. Researchers decided to test if this messenger could be used to block learning impairment in sleep-deprived flies. Seugnet genetically altered a line of flies so they made more copies of a dopamine receptor in brain regions known as the mushroom bodies. These areas are roughly equivalent to the human hippocampus, which is involved in learning and memory.
Sleep-deprived flies with extra dopamine receptors could still learn as if they had a full night's sleep, Seugnet found.
"Using this gene and other related genes, we may be able to find better ways to boost performance for someone like a relief worker who's had to stay awake for six straight days trying to save people trapped by an earthquake," Shaw says.
"I want to emphasize, though, that this type of treatment would just be for people who absolutely have to stay awake," he adds. "It's not about trying to cram too many hours in your dayeveryone else should just suck it up and get a good night's sleep."
Shaw is currently examining the role of related genes in sleep and learning. He is also testing whether sleep deprivation in young flies impairs brain development.
|Contact: Michael C. Purdy|
Washington University School of Medicine