A protein that helps the brain develop early in life can fight the mental fuzziness induced by sleep deprivation, say researchers at Washington University School of Medicine in St. Louis.
"It's interesting that NOTCH, a protein that plays such a prominent role in development, also has important functions in the adult brain," said senior author Paul Shaw, associate professor of neurobiology.
"To our surprise, we found if NOTCH activity is boosted in the brains of sleep-deprived fruit flies, the flies can continue to stay sharp and learn after sleep deprivation. They behave as if they had a full night's sleep," added Shaw.
Shaw and his colleagues tested flies' ability to learn by pairing a negative stimulus (the chemical quinine, which flies prefer to avoid) with a positive stimulus (a light, which flies instinctively seek).
When offered an opportunity to enter a darkened tube or a lighted tube with quinine, flies that can learn suppress their natural desire to choose the light. Flies, like humans, show a progressive decline in cognitive performance during the course of a typical waking day. Prolonged disruption of sleep causes a much sharper drop in learning.
Shaw became interested in NOTCH when his group found that sleep deprivation in flies caused increased activity in a gene that suppresses NOTCH. They found a similar increase in humans following sleep loss.
They went on to show that when that suppressor is genetically disabled, allowing increased NOTCH activity, flies continue to learn even when sleep-deprived.
The study has been published in Current Biology.