We spend approximately one third of our lives sleeping, but do we really understand exactly what happens while we're catching some zzz's?
In spite of the fact that you may feel like you're not doing much while sleeping, your brain would beg to differ.
During sleep, the body cycles through 5 different stages of sleep. During each phase, the body and brain work together to complete many
complex processes such as stress relief, tissue growth and repair, and memory storage, to name a few.
In fact, during certain stages of sleep, neurons in the brain fire at about the same rate as they do when we are awake. This is because
the brain is going to work. During sleep, the brain can finally devote time to do some "house cleaning". This type of "house cleaning" can only be done while
we sleep, when all available energy can be devoted to this task.
Toxic Waste Removal
During sleep, the brain works very hard to "clean out" toxic protein waste that builds up during the day. Many neuroscientists refer to
this as the brain doing "housekeeping", or they liken the process to a "dishwasher". This is because during the day waste from proteins
starts to build-up, but removing this waste is very energy consuming and requires brain cells to actually shrink so that cerebrospinal
fluid can circulate through the brain, removing the toxic build-up on its way out. When we are sleeping we do not need energy to walk, speak, eat,
or complete any other tasks which might use energy. Our brain takes advantage of this precious "free time" and gets to work.
Why We Sleep
Scientists hypothesize that this intricate process is the most likely reason why animals and humans need to sleep. It also helps explain
why poor sleep is linked with Alzheimer's and memory loss, which are also linked with a build-up of beta-amyloid (a protein).
Russell Foster explains in a
2013 Ted Talk
"What's turned out to be really exciting is that our ability to come up with novel solutions
to complex problems is hugely enhanced by a night of sleep. In fact, it's been estimated to give us a threefold advantage. Sleeping at night
enhances our creativity. And what seems to be going on is that, in the brain, those neural connections that are important, those synaptic
connections that are important, are linked and strengthened, while those that are less important tend to fade away and be less important."
Make Sleep a Priority
We still have a long way to go when it comes to understanding exactly how these mechanisms work. However, the fundamental understanding
that the brain needs sleep to "clean house" adds to the long list of reasons why it is important to prioritize a good night's sleep.
For more on the importance of sleep and tips on how to sleep better,
check out our blog