In experiments involving zebrafish, the researchers investigated whether DNA damage triggers the buildup of fatigue and subsequent sleep. It turned out that after the accumulation of a certain level of DNA damage, the fish had a desire to sleep and eventually fell asleep. During sleep, the amount of these injuries decreased.
After that, scientists determined how many hours it takes a zebrafish to fully rest. It turned out that six hours are enough for her.
In addition, experts have come to the conclusion that the protein PARP1 is one of the first to signal the need for sleep in the brain. Moreover, if you suppress the activity of this protein, then fatigue will not be recognized: in this case, the fish did not understand that they were tired and that they needed sleep to restore the damaged DNA.
Also, the role of PARP1 in the regulation of sleep has been confirmed by experiments in mice. With a decrease in the activity of this protein, they decreased the duration and quality of sleep.