Back when I started working in what we called at the time “electronic data processing,” “EDP” for short, application systems didn’t stay up 24/7 like they do now. There were some that did, but they were the exception, not the rule. Typically, after everyone went home for the night, an application would be shut down, and the operations staff would run “batch processing and maintenance.” Jobs would be run to back up the databases and files, programs would run to see if any transactions needed to be completed, to report on what happened throughout the day, and to reorganize the files and databases, so that when people showed up for work the next morning, everything would be ready for them.
This is how the brain functions when you go to sleep. While you’re off in Dreamland, your brain is busy connecting the new information you picked up during the day with information that had been there before, building new associations, and, most importantly, taking out the garbage. I read an article from 2013 on the BBC’s website that says a US team has learned that the brain uses the downtime that sleep provides to flush the damaged proteins that have accumulated during the day as a result of mental activity.
The team was studying the glymphatic system, the brain’s waste removal system analogous to the lymphatic system, in mice, and found that it is ten times more active while the mice were asleep. Cells in the brain shrink during sleep, increasing the interstitial space and allowing more fluid in to wash away the damaged proteins that have built up. Sleep time allows the brain to focus its energy on this important task; during the day, that energy is reserved for mental activity. Studies suggest that diseases such as Alzheimer’s and Parkinson’s, where brain cells are destroyed, might be directly related to the buildup of toxic material in the brain.
I haven’t seen any followup articles to this, but if all of this is true, and the brain does all of this while you’re asleep, it suggests that getting a good night’s sleep might be part of the key to preventing degenerative diseases of the brain, as well as being important to physiological and psychological well-being. Which we all knew intuitively, but it’s always good to get confirmation.
What do you think of all of this? And how’d you sleep last night?