If you've ever had an overbearing parent or partner tell you you're lazy for having a lie in, well, HA! The joke's on them, as their early rising ways probably means that their brains are full of nasty neurotoxins, according to new research.
As well as curing us of that sleepy feeling, US researchers have found that, while sleeping, the brain undergoes a cleaning cycle to rid itself of toxins and waste proteins that build up during the day. The glymphatic system, which is basically a plumbing system for your brain, sees the glial cells shrink during a decent night's sleep, increasing the gap between brain tissue and allowing fluids to flush away the built-up trash. It's a necessary process for helping in the retention of memories and learning it seems, and could also be a factor in medical conditions such as Alzheimer's or Parkinson's disease.
Dr Maiken Nedergaard of the University of Rochester Medical Centre offers a fitting analogy for a Friday night:
"You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can't really do both at the same time [...] The brain only has limited energy at its disposal and it appears that it must choose between two different functional states - awake and aware or asleep and cleaning up." [Science Mag via BBC]