The reason why we need to sleep, is not only that the body needs rest. During sleep the brain goes into a different condition in which gets rid of the toxic by-products of neural activity. A similar process occurs when sleep is critical is not enough – but in this case, the brain is unable to stop in time, and together with “trash” cleans the neurons and synapses that are not co-products. If to draw an analogy, the mind does not only potato peels and cartons of eggs, but also a wardrobe, an armchair and a beloved dog. Even if a person tries to make energy, slept late recovery of neurons and synapses does not occur, a wardrobe and a chair (and the dog) remain in the garbage.
A group of specialists from the Polytechnic University of Marche (Marche Polytechnic University, Italy), led by neurologist Bellesi Michele (Michele Bellesi) investigated the mammalian brain to understand how animals react to lack of sleep, and found that between sleep and suffering from severe sleep deprivation, the mice have a strange resemblance. Neurons in the brain, like other cells, are constantly being updated and during this process answer in glial cells. During phagocytosis they are “clean” of unwanted cells. For updating the synapses respond astrocytes. And astrocytes, and glial cells are active during sleep, but, as shown by experiments, they also work during lack of sleep, and with significant overtime, in result, the brain loses a large number of healthy cells.
The researchers studied the brains of mice, divided into four groups:
By measuring the activity of astrocytes, the research group found that the first group of astrocytes was active in 5.7% of synapses. The second – already at 7.3%. Astrocytes of the third group showed activity in 8.4% of the synapses, and the fourth, not sleeping for a long time, at 13.5%. Thus in the first place destroyed those synapses that were used most often. With glial cells and neurons was the same thing – in mice with chronic lack of sleep the brain actually started to eat itself, destroying the nervous cells and connections between them. Such activity of glial cells characteristic of these neurodegenerative diseases, such as Alzheimer’s disease. As for astrocytes, their phagocytosis occurred mainly in acute and chronic lack of sleep, sudden awakening didn’t make the astrocytes to destroy synapses.
Scientists have noted an increased risk of sleep deprivation, pointing out that it is a chronic lack of sleep causes these glial cells to Express activity. Given the fact that in recent years significantly increased the number of deaths from Alzheimer’s disease, according to experts, it is necessary to pay special attention to the quantity and quality of sleep.