The brain gets rid of some 1.5 kilograms of waste products a year, equivalent to its own weight. One puzzle: Where does its built-in garbage disposal reside? New findings that reveal detritus-carrying passages—what is called the glymphatic system—traffics the brain’s discarded leavings.
Much of this activity, moreover, occurs during sleep. Manipulating the glymphatic system may be a new way to treat Alzheimer’s and other neurodegenerative diseases by removing buildups of toxic proteins. Watch a talk on the glymphatic system by Maiken Nedergaard, author of “Brain Drain” in the March Scientific American.