Scientists Are at the Brink of Finding Out Why We Sleep

The question of why do we sleep has been troubling scientists for a long, long time. However, a recent Bar-Ilan University study on zebrafish and mice provides a giant leap towards answering this riddle.

Namely, the results show that DNA damage in nerve cells builds up during waking hours, which triggers a DNA-damage-alert protein (named Parp1) to accumulate in them. This, in turn, induces the need for sleep in both zebrafish and mice.

The need for the nervous system to go into an alternative state such as sleep so that our internal mechanisms can do more efficient DNA repair seems quite reasonable. The state of sleep has been detected in every living organism with a nervous system.

But what is DNA damage?

DNA—the genetic material we carry in almost every cell in our body, is prone to breakage and damage due to different environmental and endogenous factors. If our ”cellular handymen” do not repair this damage through proteins, the cell containing the damaged DNA will develop deformities or die.

The nervous system is in constant working mode during the day, so DNA damage accumulates rapidly, and with it, Parp1. Scientists observed that the zebrafish started to sleep after a certain threshold was reached for the concentration of this protein.

However, when researchers inhibited the Parp1 buildup through various means, the fish weren’t sleepy at all. What’s more, they repeated the experiment in mice and got the same results.

But, what about humans?

An earlier study on the effects of sleep deprivation revealed a link between DNA damage in humans (doctors in this case) and the lack of sleep, but it didn’t go into details. 

Nevertheless, knowing that we probably share these physiological mechanisms of sleep with zebrafish and mice should motivate us to seek relief from sleep disorders through any available means, from meditation to natural sleep aids to medication.

If we don’t, we risk irreparable damage to our nerve cells.