Alzheimer's finding a real eye-opener
Extra sleep can help fruit flies overcome Alzheimer's disease-like memory problems, according to new research out of Washington University School of Medicine in St. Louis.
“It has to be the right kind of sleep, and we're not sure how to induce this kind of slumber in the human brain yet,” said senior author Paul Shaw, Ph.D., associate professor of neurobiology. “But our research suggests that if we can learn how, it could have significant therapeutic potential.”
Scientists intentionally disabled a gene responsible for memory in three groups of flies. The first developed a condition similar to Alzheimer's. Another had a hard time reinforcing new connections to encode memories. In the third, the disrupted gene left the flies with too many connections.
The study, published online in Current Biology, showed the flies could cope with any of the conditions with increased sleep.
The research team used three techniques to increase sleep: stimulating a cluster of key brain cells, boosting production of a sleep-related protein, or giving the flies a drug that mimicked a chemical messenger.
Three to four extra hours of sleep per day for as few as two days restored the flies' ability to make memories. The gene was still disabled, but Shaw said the additional sleep helped the brain create a “work around.”
“In all of these flies, the lost or disabled gene still does not work properly,” noted lead author Stephane Dissel, PhD, a senior scientist in Shaw's lab.
“Sleep can't bring that missing gene back, but it finds ways to work around the physiological problem,” Dissel added.
Shaw and others believe sleep helps the brain reinforce connections between brain cells that encode important memories and cut back connections that encode useless information.
Shaw works with fruit flies to explore the brain mechanisms that control sleep, which he and others have shown to be similar to those seen in people.
Alzheimer's disease is the most common cause of dementia.