This is how sleeping helps repair the body

For the first time, the brain circuit that allows the body to repair itself during sleep has been seen in action in mice . When we sleep, the brain produces growth hormone , or GH, which acts on bones , cartilage , muscles , and the liver , stimulating the construction of tissue . However, the ways in which this mechanism occurs had until now remained a mystery. The result, published in the journal Cell by a research group led by the University of California, Berkeley, is important for understanding various aspects of health and could lead to future therapies for several diseases typically accompanied by sleep disorders, such as type 2 diabetes and Alzheimer's . Researchers coordinated by Yang Dan recorded the neural activity of mice during multiple sleep-wake cycles , discovering that growth hormone is released differently both during REM sleep , the period characterized by rapid eye movements under the eyelids, and during other phases. Furthermore, a circuit involving neurons in the locus coeruleus , the part of the brain linked to wakefulness, was also discovered. "This suggests that sleep and growth hormone form a perfectly balanced system ," says Daniel Silverman, one of the study's authors. "Too little sleep reduces GH release, while too much of it can in turn push the brain toward wakefulness. This balance," adds Silverman, "is essential for growth , repair , and metabolic health ." Growth hormone, in fact, also regulates the metabolism of sugars , fats , and proteins in adults. Without the right amount of the hormone, due to lack of sleep, the risk of obesity, diabetes, and other cardiovascular diseases increases, so the data obtained could also be useful for these pathologies.