Getting extra hours of sleep in at night could fix memory problems, according to a recent study.

Many studies have linked more sleep to better memory, but researchers at Washington University in St. Louis found that extra sleep helps the brain overcome neurological deficiencies that could block memory formation.

For the study, researchers examined three groups of fruit flies. They interfered with their ability to remember by disabling a different critical memory gene in each group.

In one group, the disabled gene led the flies to develop a condition with similarities to Alzheimer's disease. In the second group, the disabled memory gene made it difficult for fly brain cells to reinforce new connections that encode memories. In the third group, the disrupted gene left the flies with too many of these connections.

"Our data showed that extra sleep can handle any of these problems," Paul Shaw, senior author of the study, said in a statement. "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, but our research suggests that if we can learn how, it could have significant therapeutic potential."

In the study, researchers restored memory in each group of flies by using one of three techniques to increase sleep. They stimulated a cluster of key brain cells, boosted the production of a protein linked to sleep or gave the flies a drug that mimicked the activity of an important chemical messenger.

Regardless of the technique used to increase sleep, the added slumber -- an extra three to four hours of sleep daily over as little as two days -- restored the flies' ability to make memories.

"In all of these flies, the lost or disabled gene still does not work properly," said Stephane Dissel, lead author of the study. "Sleep can't bring that missing gene back, but it finds ways to work around the physiological problem."

The findings are detailed in the journal Current Biology.