Most people need eight hours of sleep per night to be working optimally during the day.
In fact, human genes programmed us what is the time needed for sleep. However, Japanese scientists discovered a mother and daughter, in which genetically lies sleeping hours are 6 instead of eight.
44-year-old woman and her 69-year-old mother for years go to bed around 22 pm and wake up fresh and rested at 4 am. In the rest of the day, both ladies were very active .
It turned out that both have a gene mutation DEC2. He "is responsible" for sleep time, we need a day.
Sleep is controlled by two processes. One is called the circadian rhythm and determines the time you usually go to bed to sleep at night and when we awaken in the morning. The second is a homeostatic process that regulates how many hours we will be with closed eyes.
It is unclear how many people worldwide have this genetic mutation. But to understand how this mutation affects sleep, the researchers experimented with mice. One group animals were with a normal gene to sleep ,the second group were with mutations.
It turned out that the second mice group slept 2 hours less than normal. But this had no impact on their activity during the day.
