Their findings build on last year’s discovery of the brain\’s own network of plumbing pipes – known as the glymphatic system – which carry waste material out of the brain.

via BBC News – Sleep ‘cleans’ the brain of toxins.

I sleep late a lot on weekends.  The Boss complains, thinks I sleep too much.  Now I can say my glymphatic system is working overtime.  And your brain needs a good cleaning…