How many hours do we need to sleep comfortably?

Just do the math to easily conclude that we spend a third of our lives asleep. Sooner or later, between warnings and sensations, there comes a time when the body gives us signals to rest. And if the body asks us, it’s for a reason.

The deepest source of the signals that motivate us to sleep is in our cells. These signals are precisely activated to repair the damage caused within you in a natural way during daily activities.

The molecular mechanisms that drive us to sleep are revealed in a recent study in animal models, as sleep is essential for all living organisms with a nervous system. It has been shown that the ultimate goal of sleep is to repair DNA damage accumulated while we are awake.

Yes that’s right! When we are awake, the homeostasis pressure that drives us to sleep – that is, fatigue – builds up in the body. We accumulate fatigue when we are active and empty ourselves during our sleep until we reach the lowest level of fatigue after a full night’s sleep.

The main cause of the increase in homeostasis pressure is the accumulation of DNA damage in neurons. During the normal functioning of all our cells, reactions are produced whose products can destroy our DNA, and thus the genes that make us who we are.

All cells possess molecular mechanisms to fight damage day and night. But neurons are more susceptible to accumulated damage when we are awake, and it reaches dangerous levels that we cannot tolerate.

Science has revealed that sleep awakens DNA repair systems, which repair it so efficiently that we wake up refreshed, better than we’ve ever been before. Therefore, the use of the metaphor of “resting sleep” makes perfect sense.

One of the first molecules to interact and activate the mechanisms that induce sleep is the PARP1 protein.

Its mission is of vital importance: it is tasked with identifying the sites of DNA that have been damaged and invoking the appropriate systems to repair them.

One of the study’s exciting findings was that when the PARP1 protein stopped working, the feeling of sleep disappeared. But this inhibition also prevents the activation of DNA mutagenic repair systems—not a good thing, as it is easy to deduce.

To check whether there is a minimum number of hours of sleep to achieve the desired restful sleep, zebrafish was used for the study – an animal model commonly used in studies on the brain, which has a sleep similar to that of humans.

After analyzing the relationship between sleep hours and DNA repair, the study concluded that six hours of sleep each night is usually enough to reduce damage to our DNA.

Among the many different neural mechanisms that regulate sleep-wake cycles is motivation.

The impulse, no doubt, makes us more likely to stay awake or stop everything and go to sleep, depending on the situation.

If we are motivated, we can maintain good physical and mental performance, for example, by writing an interesting article, reading a good book or dancing at a live party – all this beyond our usual working hours and ignoring the pressure of homeostasis.

It is clear that the formation of relationships with others of the same species, opportunities for mating and the presence of predators, in nature, generate stimulatory responses that modulate states of excitability.

There are animals that can stay awake or sleep much longer than usual, and even keep only half of their brain awake, with one eye open.

Something similar happens in humans when we sleep in a different bed than we do on a flight, which is known as the first night effect. Therefore, it is very important to know as much as possible the processes that modify wakefulness and its relationship to staying awake or sleeping, in order to avoid sensitive and even conflicting situations.

Given its meaning and its relation to the topic, we end with the first verses of oh sonoArgentine poet Jorge Luis Borges:

If sleep (as they say) a

truce, peace of mind,

Why did you suddenly remember

Do you feel robbed of a fortune?

* Francisco José Esteban Ruiz is Professor of Cell Biology at the University of Jaén, Spain.

This article originally appeared on the Academic News website Conversation Republished under a Creative Commons License. read here The original version (in Spanish).

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