The researchers say that the waste material includes poisons, or toxins, responsible for brain disorders such as Alzheimers disease.

　　They also found that during sleep, the brains cells shrink, or become smaller. This shrinking permits waste to be removed more effectively.

　　Dr. Nedergaard says these toxins end up in the liver. There, they are broken down and then removed from the body.

　　So our study suggests we need to sleep because we have a macroscopic cleaning system that removes many of the toxic waste products from the brain.

　　The brains cleaning system could only be studied with new imaging technologies. The test animal must be alive in order to see for this brain process to be seen as it happens.

　　Dr. Nedergaard says the next step is to look for the process in human brains. She said the results demonstrate just how important sleep is to health and fighting disease. The research may also one day lead to treatments to prevent or help fight neurological disorders.

　　7 Tips for Better Sleeping

　　Do you have trouble sleeping? Not being able to sleep is called insomnia. According to the United States National Sleep Foundation, here are some tips for a good nights sleep:

　　Go to bed about the same time each night, even on weekends. This helps to set your bodys sleep clock.

　　Exercise every day.

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