The purpose of sleep - help a person to forget all the excess, in order to better remember right. Two new scientific papers published in the journal Science, supports this theory, known as "synaptic homeostasis hypothesis".
In one of the reports authors hypothesis, experts from the University of Wisconsin Giulio Tononi and Chiara Cirelli, describe an experiment to study the size and shape of synapses - nerve impulse transmission sites - in the brains of experimental mice. It turned out in particular that the sleeping animal such contact zone 18% less than in awake. Such a significant difference surprised even the experts themselves.
In the second case, the University of Johns Hopkins Graham Deering studied to test the hypothesis of the same proteins in the brain of mice. As a result, the protein was found under the symbol Homer1A, playing, as can be seen, an important role in the "truncation" of synapses during sleep. With the help of experiments on genetically modified mice, scientists were able to experimentally confirm that the presence or absence of Homer significantly affect the memory of animals and, consequently, on their behavior. In particular, according to the estimates of the authors, sleep does not erase frightening memories in mice without this protein, which continued to hamper them. In the control group, after the fear of sleep passed.
Describing this work, the newspaper The New York Times made a reservation that, as the experts warn others, "the new results are not unequivocal evidence of (correct) hypothesis of synaptic homeostasis". As told fellow Ohio Medical Institute sleep Marcos Frank, "a great work, but the question is whether this is one of the sleep function or the main function."