Why do we need sleep?
We don’t know is the simple answer. We know that we feel better and function better. What we don’t know is whether there is a neurochemical or molecular basis of the need to sleep. Recent research is beginning to shed light on this matter.
Sleep now seems to be the mechanism to keep the brain functioning properly.
It has been shown that sleep deprivation leads to Attention deficits/lapses, cognitive deficits, depressed mood and problems with memory formation.
Restricted sleep which is sleep less than 7 hours per night when present chronically causes cognitive dysfunction within just a few days, similar to that seen with acute total sleep deprivation.
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Brain repairs itself while you sleep. Some insights.
The brain has what has been called “Garbage truck” system. This is the Glymphatic system which shares similarities to the body’s lymphatic system. These are channels that clear debris and metabolites from the brain. One of the very important metabolites removed is called Beta Amyloid. In the sleep state the Garbage truck mechanisms of the brain are much more active than in the awake state. In the awake state Beta Amyloid accumulates in the brain. Sleep state is needed to remove it. It is now known that accumulation of Beta Amyloid can lead to brain degeneration and can cause Alzheimer’s and Dementia.
The horrifying brain damage from lack of sleep.
Some amazing research was published in 2017. It is no 5 in the reference section.
The study showed that that the normal process of brain debris cleaning ramps up significantly with sleep deprivation. The process starts to destroy the brain. The brain literally starts eating itself. A type of Glial cell called Astrocyte is part of the Garbage truck system. It cleans out the synapses by a process called phagocytosis ( a process of eating of material by cells). This eating process is needed to remove worn out material and remodeling. An excess of this process may destroy synapses that did not need removal.
In mice, a well rested brain shows astrocyte phagocytic activity in about 6% of brain synapses. In chronic sleep deprivation this number can be as high as 15.5%. This process at a sustained elevated level goes from being protective to damaging.
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Author’s comments.
Lack of sleep may cause neurodegenerative diseases in more than one way. Science is beginning to find the major mechanisms of how adequate sleep protects your brain. The details of the effects of lack of sleep as the brain starts eating itself is truly disturbing. We are just scratching the surface when it comes to neuroscience. Much more will be known in coming years. I hope we all retain able cognition to enjoy our loved ones and the world around us for a long time to come. It seems that without adequate sleep this will be impossible. So no matter what, get the 8 hours of recommended sleep every night.
REFERENCES:
- Sleep: the brain's housekeeper?. https://www.ncbi.nlm.nih.gov/m/pubmed/24136944/
- Garbage truck of the brain. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749839/
- Behavioral and physiological consequences of sleep restriction. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978335/
- The Neuroprotective aspects of sleep. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651462/pdf/nihms734829.pdf
- http://www.jneurosci.org/content/37/21/5263