We've all experienced the intense struggle to pay attention after a bad night's sleep — and a new study shows what happens in the brain as that feeling arises.
When you zone out after pulling an all-nighter, the brain flushes out cerebrospinal fluid (CSF), which surrounds the brain and spinal cord and is part of the brain's waste-disposal system. This CSF then floods back into the brain when you snap out of it, according to the study, published Oct. 29 in the journal Nature Neuroscience.
-copy-dd1f2bf0.jpeg?w=600)
