It wasn’t very long ago that scientists discovered a mechanism for the brain to remove toxins, called the glymphatic system, and now can link its efficiency to the quality of sleep. The glymphatic system behaves much the same way as the lymphatic system but is managed by glial cells in the brain. Cerebrospinal fluid (CSF) supplies nutrients to and removes toxins from the brain. The glymphatic system is like plumbing that surrounds the blood vessel; it enhances the removal of toxins. Astrocytes (star-shaped glial cells) use projections to form a sort of circulatory network outside of the arteries and veins. CSF is pumped through the brain along these channels, draining toxins. Maiken Nedergaard, M.D., D.M.Sc., a member of the research team stated, “It’s as if the brain has two garbage haulers – a slow one that we’ve known about, and a fast one that we’ve just met. Given the high rate of metabolism in the brain, and its exquisite sensitivity, it’s not surprising that its mechanisms to rid itself of waste are more specialized and extensive than previously realized.”
New research shows the efficiency of toxin removal from the brain is linked to how deeply we sleep, which has far-reaching implications for depression, neurodegeneration and even dementia. The researchers looked at the brains of mice and tracked brain electrical activity. The mice in the study were given drugs to replicate the slow and steady electrical activity found in deep sleep, which also happened to promote the optimal functioning of the glymphatic system.
Toxic proteins, like beta amyloid and tau proteins, in the brain are linked to neurological dysfunction. It is possible that impairment of the glymphatic system due to disrupted sleep keeps the brain from removing the toxins, which could be driving the dysfunction, once again highlighting the link between sleep, aging and neurological impairment. Dr. Nedergard states, “These findings also add to the increasingly clear evidence that quality of sleep or sleep deprivation can predict the onset of dementia.”