This Is the Real Reason We Need Sleep

[Jilly_in_VA]

Humans spend a third of their lives curled up in bed, and scientists have no idea why. The theories for why animals sleep range from energy conservation, to helping our brains store memories and new information, to being an evolved behavior that keeps us from venturing out into the dangerous night. Scientists have never been able to pinpoint which of these theories, or any others, are really the case.

Turns out there might be a much smaller but no less crucial reason why living critters like us need to hit the hay every day. In new findings published in the journal Molecular Cell, researchers from Israel’s Bar-Ilan University think the main reason we evolved to sleep was that it activates the systems within our body that repair damaged and broken DNA.

DNA in our cells accumulate damage due to UV light, radiation, increased physical and biochemical stress, and even just simple errors our body makes. Our body has repair systems to repair these cracks and flaws in the DNA in our cells, but these repair systems function much more effectively during sleep hours than wakeful ones, presumably because the body can devote more resources to repair.

This is especially true for DNA in our neurons—the most fundamental part of our brains. “During wakefulness, neurons are busy with so many different things,” study co-author Lior Appelbaum told The Daily Beast. The new study demonstrates that the longer you stay awake, the more damage is inflicted on your neuronal DNA, at a rate that’s faster than what your repair systems can accomplish. If your repair systems aren’t allowed to function at optimal settings, the damage can reach dangerous levels that can temporarily or even permanently harm the brain.

https://www.thedailybeast.com/we-need-sleep-because-it-helps-repair-dna-damage-in-brain-cells-new-study-finds?ref=home

[stopdiggin]

1. super interesting. this is great!

I knew that nap was making me bright as a shiny new penny! And raspberries to all that scoffed these many years ...

[jmbar2]

2. Yay for naps!

You always find the most interesting articles, Jilly. This made my day.

Now time for my afternoon DNA restoration.

[C Moon]

8. Love naps! Love the funny little dreams I have during a nap.

[krispos42]

3. If we didn't sleep, how could we celebrate holidays?

Can't have a Memorial Day Mattress Event if we don't sleep!

[Wicked Blue]

4. Rip Van Winkle must have had supercharged neurons nt

[dickthegrouch]

5. The real question now though

Is whether that DNA repair occurs if the sleep has to be induced artificially with soporifics, tranquilizers, or alcohol?
I have had sleep problems all my life and the answer would appear to be “yes”. But I’d appreciate knowing which of the many sleep inducers are actually beneficial and which to avoid.

[Bernardo de La Paz]

6. Ignorant writers write things about sleep like "scientists have no idea why"

They have many ideas and lots of data and evidence.

[American Interregnum]

9. True

Besides which, who in the hell would rather be awake all the time? I say, if it's good enough for the other animals, it's good enough for us, because we're not nearly as special as we think we are!

[enki23]

12. Not to mention the implicit assumption such thing exists as "the" reason.

If there is a "the reason" we sleep, it's that our evolutionary linage has left us that way. The "functions" of sleep, which involve an entirely different set of questions and concerns, appear to be numerous and varied. Most of them seem related to learning, memory, and tissue repair.

Sleep seems to perform a lot of important functions for us. I think it's also worth mentioning that the need for sleep creates significant, sometimes fatal vulnerabilities.

[Bernardo de La Paz]

7. I hope nobody gets a m y p ill ow ad while reading this or the article. . . . nt

[airplaneman]

10. I have always thought of sleep as your bodies way of sorting out the days events. n/t.

[Buckeye_Democrat]

11. Very interesting! Thanks!

From the article:

The study had two major parts. In the first, the Bar-Ilan team used tools like irradiation and drugs to induce DNA damage in zebrafish, and found that that increased damage led to an increased need for sleep so that the body could run repair systems. The minimum amount of sleep needed was six hours—anything less meant that the zebrafish could not adequately repair their DNA.

In the second part, Appelbaum and his team used gene-editing tools to play around with a protein called PARP1, which tells the body what parts of the cell’s DNA need repair. The researchers found that increased amounts of this protein in the zebrafish promoted more sleep, and therefore more sleep-dependent repair. Inhibition of PARP1 meant the fish didn’t go to sleep, and therefore didn’t repair their DNA well. A separate set of trials on mice confirmed the PARP1 connection.



As a side-note, zebra fish have the same gene that's defective for me and some of my siblings. It causes some unusual calcification of soft tissues (mostly causing blindness for most people with the condition). And I've noticed that the abnormal calcification usually happens near the location of endochondral bones (the bones that increase in size by replacing cartilage with bone as we grow), such as the sphenoid bone behind the eyes, but I've never seen that pattern mentioned in science articles about it.

Anyway, zebra fish with that same genetic problem don't even survive birth. Their bones are too much of a mangled mess! So humans apparently have other genes to help compensate for the problem.

When I first read about zebra fish having the same gene, I thought, "Suuure we didn't evolve. Uh huh!"

Using them for this study is plenty compelling to me!

[Collimator]

13. I have long believed. . .

That dreams are like the garbage disposal for our minds. We take in so much sensory information as we go about our days, in addition to running our inner psychodramas, that I think our brains grind up all that sensory input to sort of rinse it away.

And there have been tons of studies about the critical importance of REM sleep for maintaining mental health. The idea that our bodies have to sort of go "off-line" for a few hours each day so our operating systems can run diagnostics and make a few repairs makes perfect sense to me.

A couple of months ago, my laptop was giving me a hard time and I kept getting "memory full" messages. But I didn't have any documents or game applications cluttering up the drive and was confused. Some knowledgeable acquaintances suggested it was because I had had my computer on for days at a time-- ironically, listening to relaxing music because I wasn't sleeping well--and that my computer's temporary stockpile of ROM or whatever needed to be emptied by shutting down my computer for a significant period of time. A quick restart wouldn't do the trick, apparently. Well, I did as instructed and my computer stopped with the annoying memory messages.

My only question now is why depression causes me to either sleep too much or too little.

[Javaman]

14. ...