The next stage is rapid eye movement (REM). During REM sleep our brains become extremely active.
This is where we dream.
In this dream state, our bodies are paralyzed, our heart rate and breathing are erratic. We are in this stage before we awake.
Scientists observed that neurons are in sync and turn off and on, and this is the only time this happens.
Now the brain needs less oxygen and less blood flow. At this point, the cerebrospinal fluid, clear fluid surrounding the brain, begins to flow in and out like a wave at high tide on the beach. This washing in and out clears the brain of toxins like beta amyloids that naturally collect in the brain and can lead to Alzheimer’s and other diseases.
So, if not enough sleep occurs, you’re leaving poison in the brain.
If the brain is not allowed to do its required maintenance because of the lack of sleep, there can be consequences in the future.
You may think that taking a nap will help you catch up on the sleep you lost. Not at all! A nap may be good to temporarily energize you, but nothing takes the place of the lengthy process your brain goes through during 7 – 8 hours of good, uninterrupted sleep!