Majicman Notes

In most bodily organs waste matter is cleared out by the lymphatic system. Unnecessary proteins, superfluous fluids and so on are carried away by special vessels to lymph nodes, where they are filtered out and destroyed.

Brain has a plumbing system of its own to flush out the junk. Cerebrospinal fluid—the liquid which suspends the brain and acts as a cushion between it and the skull—was actively washing through the organ by hitchhiking on the pulsing of arteries and veins that happens with every heartbeat. The fluid was collecting trash and carrying it out of the brain to lymph nodes for disposal

From the first studies of the glymphatic system, it was clear it might be involved in preventing Alzheimer’s disease. Alzheimer’s is caused by a build-up of two types of proteins, amyloid-beta and tau. These aggregate to form plaques and tangles that stop neurons working properly and eventually lead to their death. When it is functioning normally, the glymphatic system clears out amyloid-beta and tau. However, in older people, or those with Alzheimer’s, this process is slower—leaving more potentially harmful proteins behind.

Giving the brain a power wash, by improving the flow of glymphatic fluid, is a potential avenue for treatment. Though the field is in its infancy, most attempts to do so have focused on an interesting quirk of the system. This is that glymphatic fluid moves through the brain only during sleep. The plumbing is disabled during waking hours, and is most active during the deepest sleep stages, switched on by slow-wave brain activity.

The Economist