Research results that DNA damage is not repaired and even risk of death when sleep is inhibited
by Wouter van Doorn
Although it is said that there are many benefits of health in sleeping, the mystery "Why do living things sleep" is in a state that has not yet been elucidated. Meanwhile, a new study showed that DNA damaged during the day accumulated in fish brain cells, and that repair work was done only during sleep. Researchers see that one reason why living things need sleep is in this "repair of damage".
Sleep increases chromosome dynamics to enable reduction of accumulating DNA damage in single neurons | Nature Communications
Sleep helps to repair damaged DNA in neurons, scientists find | Science | The Guardian
This study was published by Lior Appelbaum who studies molecular neuroscience at Bar-Iran University in Israel and David Zada, a student of Appelbaum. Two researchers started hypothesis that they hypothesized that "if sleep develops in all organisms with nervous system, sleep should function according to the level of each neuron" did.
To verify the hypothesis, they genetically engineered the zebrafish to allow observation of the movement of the chromosomes in the neurons. When observation was carried out using a special microscope, it was confirmed how chromosomes move in the neuron and how frequently the DNA breaks while zebrafish is awake or sleeping.
According to researchers, chromosomes do not move very much while zebrafish is awake, and the molecular chains of broken DNA are accumulated in the neurons in the normal range of living organisms. did. And when inhibiting zebrafish sleep, some of the neurons accumulate damage on DNA, which seems to be so serious that there is a danger of death.
However, when the zebrafish took a deep sleep, the chromosome started to move at twice the rate when it was awake and the damage of the DNA accumulated in the neuron decreased. Even during the day even if you add sleeping pills to the tank and let the fish sleep, the same thing has happened, so it is considered that "sleep" itself is not "time to sleep" but DNA repair effect itself. Appelbaum explains that DNA damage in different places can be repaired by the cell's repair mechanism by moving the chromosome and changing shape. If a fish is up, the repair work can not catch up with the speed at which damage accumulates, but the repair mechanism can work well while sleeping.
Appelbaum says about this discovery "There is one key" Why do we sleep? "" Offline time gives us the time to clean up for the next day and then awakens and makes you busy again It gives me a fresh start before. " Since the neuron accumulates much damage when it is tired, the brain needs to go to sleep for damage repair.
Researchers are going to experiment with mice following zebrafish. Although the activity of the brain differs between fish and mammal, it is expected to confirm how mouse chromosome movement and DNA repair are performed.