While it is not possible to catch up or make up for lost sleep, a new study shows a good restful night will cleanse the brain of toxins, according to a news release.

The new research, published Thursday in the journal Science, could offer scientists a new perspective on the biological purposes for sleep and how it physical affects the brain. The researchers found a new system that disposes toxins and waste while sleeping.

"This study shows that the brain has different functional states when asleep and when awake," said lead author Maiken Nedergaard, M.D., D.M.Sc., co-director of the University of Rochester Medical Center (URMC) Center for Translational Neuromedicine. "In fact, the restorative nature of sleep appears to be the result of the active clearance of the by-products of neural activity that accumulate during wakefulness."

Named "the glymphatic system," the brain uses a system highly active during sleep to flush toxins known to cause Alzheimer's and other neurological disorders. To aid in the removal of this waste, the researchers noticed brain cells reduced in size during this process.

Often tackled as a philosophical or psychological question, the purpose of sleep has stumped scientists looking for a scientific explanation. Sleep was seen as an evolutionary vulnerability for many animals who leave themselves open to sneak attacks from predators. Scientists could not pinpoint a benefit that outweighs this vulnerability but still acknowledged the need for sleep is inherent in almost all mammals.

"The brain only has limited energy at its disposal and it appears that it must choice between two different functional states - awake and aware or asleep and cleaning up," said Nedergaard. "You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can't really do both at the same time."

Nedergaard and her colleagues' work seems to have given scientists that long-sought-after explanation.

"These findings have significant implications for treating 'dirty brain' disease like Alzheimer's," said Nedergaard. "Understanding precisely how and when the brain activates the glymphatic system and clears waste is a critical first step in efforts to potentially modulate this system and make it work more efficiently."