How to Dream Clears Alzheimer ;
In the laboratory, beta-amyloid disappeared twice as fast during sleep. Beta-amyloid is a prime suspect behind Alzheimer’s disease. Find out how sleep distance amyloid that cause Alzheimer dangerous doubles.
Scientists and philosophers have wondered why people sleep and how it affects the brain. Sleep is important for storing memories. It also has a restore function. Lack of sleep affects reasoning, problem solving, and attention to detail, among other effects. However, the mechanisms underlying these benefits of sleep are unknown.
Dr. Maiken Nedergaard and colleagues at the University of Rochester Medical Center recently discovered a system that drains waste from the brain. Cerebrospinal fluid, a clear fluid surrounding the brain and spinal cord, moves through the brain along a series of canals that surround blood vessels. The system is managed by glial brain cells, so researchers called the glymphatic system.
Scientists also reported that the glymphatic system can help eliminate a toxic protein called beta-amyloid from brain tissue. Beta-amyloid is recognized by the accumulation in the brain of patients with Alzheimer’s disease. Other research has shown that brain levels of beta-amyloid decreased during sleep. In their new study, the team tested the idea that sleep might affect beta-amyloid clearance by regulating glymphatic system. The work was funded by the NIH National Institute of Neurological Disorders and Stroke (NINDS).
The researchers first injected a dye into the spinal fluid of mice and monitored the electrical activity of the brain as they tracked the flow of dye through brains of animals. As reported in the October 18, 2013, edition of Science , the dye flowed only when the mice were awake. In contrast, when mice were unconscious-asleep or flowed-anaesthetized quickly.
Changes in the way fluid moves through the brain between conscious and unconscious states may reflect differences in the available space for movement. To test the idea, the team used a method that measures the volume of space outside the brain cells. They found that this “extracellular” volume increased by 60% in the cortex of the brain when the mice were asleep or anesthetized.
The researchers then injected mice with beta-amyloid label and measured the duration of their brains when they were asleep and awake. Beta-amyloid disappeared twice as fast in the brains of mice that were asleep.
Glial cells flow control through glymphatic system for reducing and swelling. Norepinephrine, a hormone that increases alertness, is known to cause the cells to swell. Thus, the researchers tested whether the hormone might affect the glymphatic system. Treatment of mice with drugs that block norepinephrine induces a sleep and increased fluid flow brain and cerebral extracellular volume state. This result suggests a molecular connection between the sleep-wake cycle and the cleaning system of the brain.
The study raises the possibility that certain neurological disorders can be prevented or treated by manipulating the glymphatic system. “These findings have important implications for the treatment of brain diseases dirty ” such as Alzheimer’s,” says Nedergaard. “Understanding precisely how and when the brain is activated glymphatic system and clears the waste is a critical first step in efforts to potentially modulate this system and make it work more efficiently.”
This article was originally published on alzheimersweekly, Read the original article here