Why is sleep so important? Why do humans ” waste” about one third of their lives on sleep? Why do animals prefer to ” sleep well” at the risk of predators? A new Israeli study found that this is because animals need to complete neuronal DNA (deoxyribonucleic acid) repair during sleep.
Although scientists have long found that sleep is crucial to all animals that have evolved nervous systems, including invertebrates such as flies, worms and jellyfish, the specific reason for this has always been an unsolved mystery. Researchers at Israel’s Bayram University reported in the new issue of the British journal Nature Communications that researchers at the university conducted animal experiments using zebrafish models. Their research can explain how sleep and sleep disorders affect brain activity, aging and various brain dysfunction.
Zebrafish is transparent and its brain nerve is similar to human. It is an ideal model to observe the changes of individual neurons. Researchers used a technique called ” 3D delayed imaging” and a high-resolution microscope to observe the brain of zebrafish and found that when zebrafish was awake, double-strand breaks of neuronal DNA accumulated continuously. When resting at night, the chromosomes of zebrafish neurons are more active, and the increase of chromosome activity will improve the repair efficiency of neuronal DNA damage.
Neuron DNA damage in the brain can be caused by a variety of reasons, such as radiation, oxidative stress and even neuronal activity. Current studies have shown that DNA damage in brain neurons will continue to accumulate and reach unsafe levels when awake.
The researchers explained that the study found physiological correlations between sleep, chromosome dynamics, neuronal activity and DNA damage. The important function of sleep is to increase chromosome activity and repair neuronal DNA damage. When animals are awake, this DNA repair process is not effective enough. It can only occur effectively during sleep and when brain information stimulation is reduced.
Apelbaum, a professor of life science at Baylan University who led the study, called the accumulation of DNA damage ” the price of sobriety.” ” It’s like a pothole in the road,” Apelbaum explained. ” The wear and tear on the road will accumulate, especially during the peak hours of the day. It is the most convenient and effective way to build roads when the roads are clear at night.”