The Glymphatic System: Your Brain’s
Nightly Cleaning Crew
Anatomy textbooks are not updated too often these days.
After the advent of the microscope, physiologists were
quick to slice, dice, stain, map, and draw every square
millimeter of the human body—and within a few short
decades, there was seemingly nothing left to explore. So it
was a major geek-out moment for biology lovers when
Jeffrey Iliff and his team at the University of Rochester
discovered what could rightly be called an uncharted organ
—the glymphatic system. This system forcefully pushes
cerebrospinal fluid through the brain while we sleep,
providing a free power-wash for our brains every single
night.
In the rest of the body, the lymphatic system is a
physical structure that collects white blood cells and debris
and slowly transfers them from the tissues to the
bloodstream and lymph nodes (those swollen lumps under
your chin when you get a bad cold are activated lymph
nodes). But unlike the lymphatic system, the glymphatic
system doesn’t have a full system of channels and nodes.
Because the brain must squeeze into a hard cavity, there
isn’t room for a large physical network. Instead, the
channels of the glymphatic system piggyback on the
drainage system of the arteries that supply the brain. In an
economical and elegant appropriation of the arterial system