When you sleep, your body not only rests and replenishes the energy needed to carry out everyday activities on a day-to-day basis. During sleep, the brain is more active, because during this process it is responsible for maintaining the body, eliminating various toxic substances produced by normal metabolism, tissue repair, and at the same time replenishes the energy required for proper physiological performance. .
Due to this, it is well known that not sleeping causes short and long-term damage in those individuals who, in some way, are deprived of sleep for prolonged periods; however, it was not understood how damaging the situation might reach before dying from lack of sleep.
At this point, a team of Italian neuroscientists from the Marche Polytechnic University led by Dr. Michele Bellesi, conducted research in mid-2018, and found that not sleeping causes the brain to eliminate a significant number of neurons, as well as a significant loss of synaptic connections; The worst thing regarding this situation is that sleep recovery might not be able to reverse the damage.
In their work, the researchers examined the response of the rodent brain to poor sleep habits and found an uncanny similarity between those mice that were relaxed and rested, and those that were sleepless.
As with cells throughout the body, neurons in the brain are constantly being renewed by two different types of support cells that often keep the nervous system stable: microglial cells and astrocytes; the former are responsible for eliminating old and damaged cells through phagocytosis (an event that occurs normally in many parts of the body, and consists of practically “devouring”), while the latter have a fundamental role in the correct maintenance and performance of the synapse.
These events orchestrated by these cells occur normally when we sleep, in order to repair the neurological wear produced during the day. However, according to the researchers, this process appears to be detrimentally activated when we subject our bodies to prolonged periods without sleep. ‘We show for the first time that key components of synapses are gobbled up by astrocytes due to lack of sleep,’ commented Dr Bellesi.
In the project, scientists analyzed the brains of 4 groups of mice. In mice deprived of sleep for days, they noted that astrocytes had increased their activity to eat building blocks at the synapse, a process known as astrocytic phagocytosis. The deleterious effect does not end there, as microglial cells also increased their phagocytic activity in those mice with chronic sleep deprivation. This is very concerning, because rampant microglial activity has been linked to brain diseases such as Alzheimer’s.
Although the studies were done with mice, these can be related to humans in a certain way, since we must remember that we have a great similarity of our genome with these murine ones.
The research is published in Journal of Neuroscience.
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