The glial cells of our brain are constantly being renewed. Their role is to phagocyte dead cells, to protect the nervous tissue. This process takes place while we sleep.

The big news is that it can also happen when you miss a lot of sleep. And that's where the problem starts, because the brain is getting damaged instead of cleaning itself up.

This great discovery was found by neuroscientist Michele Bellesi. On May 24, 2017, he published in the Journal of Neuroscience a study that says that lack of sleep permanently damages the brain. To arrive at this conclusion, Dr. Bellesi, accompanied by his team of five scientists from Marche Polytechnic University, studied the effect that lack of sleep could have on four groups of mice. The first slept between 6 and 8 hours, the second slept intermittently, the third did not sleep for 8 hours and the fourth remained awake for 5 days.

The results for the first two groups, those who had received adequate sleep, showed that synapses (the area of contact between two neurons) were regenerated between 5.7% and 7.3%. While for the two groups that had not slept, the scientists noticed that the astrocyte phagocyte (the astrocytes that eat the synapses) had increased its activity by 8.4% and 13.5% in the brains of these mice.

This experimentation also demonstrates that lack of sleep increases the production of MERTK proteins which facilitates the phagocyte cells, and therefore increases the risk of Alzheimer's. However, these results have not yet been proven on the human brain, so, for now, you can still spend your nights on Netflix.