Sleep is a wonderful thing – wonderful, yet incredibly bizarre. Most, if not all, animals sleep. Have you ever stopped to question, ‘why?’ Many neuroscientists speculate on the reason why we sleep. Come to think of it, sleep is the most vulnerable time of the day. It’s when consciousness shuts off, and we’re left unable to fend for ourselves. However, vulnerable as we may be, it’s a fact that evolution still hasn’t found a way around it, though. So why is sleep so important?
A new theory begs to answer the question: Sleep is when our brains take out the trash.
A study emerging from the University of Rochester has found that the glymphatic system, the system responsible for flushing toxins out of the brain, is nearly 10 times more active when we are asleep. With the utilization of blood vessels, the glymphatic system clears brain tissue by pumping in spinal fluid, flushing waste into the circulatory system.
In the experiment involving mice, their glymphatic systems were notably 10 times more active during sleep. They explained that this is due to the amount of energy necessary to do this. Only in sleep is the brain able to take a rest from most of its cognitive functions, and fully devote energy into clearing away the trash from the brain. In fact, it was noted in the study that the sleeping brain even has the ability to remove proteins in the brain that help promote the onset of Alzheimer’s.
“The brain is a finite entity. It has a limited amount of energy at a time, and it seems as if it must pick between its two functions: raw, processing power while awake, or cleaning up the mess while asleep. It’s like having a party at your house. You should only be either entertaining the guests, socializing, or be cleaning up afterwards. You can’t be doing both at the same time.”
Dr. Maiken Nedergaard, Co-director,
University of Rochester
The study also noted that the brain shrinks up to 60% in size while asleep, allowing waste to be more easily flushed out.
Without the brain’s glymphatic system, toxic proteins accumulating in the brain would create the onset of possibly various different brain disorders – most of which is directly linked to the accumulation of waste in the brain. In future applications, if we are able to find a way to utilize the glymphatic system more effectively, we might just be able to cure Alzheimer’s and other degenerative brain disorders.