Sleep has been found to be a garbage disposal system for the mind and the brain. During sleep, the brain’s neurons get smaller and the spaces between them allow fluids to wash away the built-up toxins and debris. Furthermore, it was discovered that the inability to properly clean away the toxins resulted in syndromes and diseases. Sleep is also vital to learning and memory. The energy of the brain is limited. That is why it desperately requires significant breaks to revitalize itself in between the normal waking states.
During these snooze times the brain did some spring cleaning of its own. It literally got its act together. And the compartmentalization of sleeping and waking was a very practical way of handling the task instituted by the brain.
What scientists couldn’t figure out was why animals slept when they could be attacked by predators during the time in which they were asleep. This remains a mystery. Meanwhile, what was a surety was that the brain’s pipelines needed cleaning time after time. This was accomplished via the glymphatic system. This system became ten times more active when an organism slept.
This finding lends credence to the physical reason behind sleep. It seems that certain degenerative diseases such as Alzheimer’s and Parkinson’s occur due to build-up of toxic products in the brain. Sleep and proper rest may be a major preventative measure against these maladies.