Scientists at Washington University School of Medicine in St. Louis have discovered a switch in the brains of fruit flies that controls their sleep, a finding which could pave the ways for treating sleeping disorder in humans.
They showed that a group of approximately 20 cells in the brains of fruit flies controls when and how long the flies sleep.
Slumber induced through this sleep switch was essential to the creation of long-term memory, directly proving a connection between memory and sleep that scientists have long suspected.
"This is exciting because this induced sleep state so far appears to be very similar to spontaneous sleep," said Paul Shaw, associate professor of neurobiology.
"That means we can manipulate these cells to explore a whole new realm of questions about the purposes of sleep. Such studies might one day lead us to more natural ways of inducing sleep in humans," he said.
The key cells are found in an area of the fly brain known as the dorsal fan-shaped body.
Scientists in Shaw's lab genetically modified the cells to increase their activity. One effect of making these cells more active was that adult flies slept for an additional seven hours a day.
When scientists added a gene that increases the cells' activity only at warmer temperatures, they could determine when and how long flies would sleep by simply adjusting the temperature in the flies' habitats.
The study appeared June 24 in Science.