In recent studies of mice brains, scientists have found that sleep actually cleans out the “junk” in the brain. Apparently, while animals are awake, proteins build up in their brains. When they go to sleep, these proteins are actually flushed out of the brain.
These findings might shed some light on why it is necessary for animals to sleep. It is also a big step for Alzheimer's researchers as well. The proteins that are flushed out of the brain while sleeping are major contributors to the memory loss of people suffering from Alzheimer's.
During the waking hours of an animals day, this junk continues to build up in their brain. If animals do not get enough sleep it will continue to build up, making it harder to get rid of after time. Originally, it was thought that enzymes actually ate away the junk proteins during sleep, and that the “clean-up crew” did not have enough time to do their jobs when an individual did not get enough sleep. It has now been proven that individuals need enough sleep so that the brain has time to expand and contract in order to flush away the toxins that are potentially harmful.
In order to do the experimentation, the scientists had to train the mice to sit still on the stage of a microscope so that they can have their brains probed. Some of the mice even fells asleep, which allowed the scientists to see the fluid flow through the brain first hand. These experiments showed that the glial cells, which is a type of brain cell, are what actually expands and shrinks to control the fluid. When these cells are changing size, the space between them changes, which allows the liquid to flow or to be stopped. The researchers have found that the space between the cells can change volume by up to 60 percent between when an individual is awake and when they are asleep.
Hopefully this research will help scientists find a cure for Alzheimer's. It will also give us depth into why animals need sleep, and even what happens during sleep deprivation. This research is very useful, and could actually change the way scientists think of the brain.