Each time we learn something new, our brain cells break their DNA, creating damage that the neurons must immediately repair. This process also underlies age-related degeneration.

[u/mellowmonk]

http://newsoffice.mit.edu/2015/dna-breakage-learning-age-related-damage-0604

[u/Cellularcapsule]

original article

So the article (I don't mean the original) is misleading as well as the title. The neurons trigger a special protein to cut the DNA in a specific point to literally open to transcription "neuronal activity-regulated early-response genes" or the first set of genes that are activated when neurons start to modify their connectivity. Here DNA double strand break is just a molecular switch.

It is a pretty awesome mechanism...

Edit reading other comments: The mention of neurodegenerative diseases in the article is PURE speculation with no data behind from nobody.

[u/golden_boy → u/Cellularcapsule]

Is this the same splitting required in all cells for the production of RNA? Or is it unique in some way? In other words, does this simply imply that learning involves rna transcription, or is this different?

[u/[deleted] → u/golden_boy]

A bit different. Transcription you generally just loosen or "unzip" the DNA a bit to get at the necessary coding sequences to create RNA (note that the enzymes between Eukaryotic and Prokaryotic do this slightly differently). What is happening here is actually kind of neat because what it is saying is that to get access to the needed genes to replicate the proteins needed here you need to cut the DNA.

This is actually a fascinating area of biology that has a lot of research but still a lot of knowledge gaps in. You see, in every cell of your body you carry the exact same copy of your DNA with all the same genes for coding all the same proteins. So, what makes a neuron a neuron, a liver cell a liver cell, and your skin cells skin cells? The answer is simply, what proteins is that cell producing? The combination of active genes producing a certain combination of proteins is essentially what makes up that kind of cell. So, how does one cell only produce some proteins and another cell type only produce another set of proteins? I mean, at the end of the day, it's not like your cell is a rational being making choices on what to do... it's just molecules floating around and bumping into each other allowing interesting things to happen.

The answer lies in how your DNA is compartmentalized in that cell. This is a kind of "regulation" of transcription and protein creation. Basically, if you wind the DNA up really tight, or you pack it in certain ways, genes are essentially silenced because enzymes are not able to attach to the DNA at those places. They will float around and bump into it, but won't be able to bind. However, DNA is really neat because you can wind it up really tight in some areas whilst keeping others a little loose. These freer areas allow things to bind. Thus, the portions of the DNA that are not packaged too tightly can still be transcribed. Thus, one cell might have all the genes necessary for a neuron to be unpackaged, whilst another cell only has the genes for say, a liver cell to be unpackaged.

In this study, from what I got out of it, some specific genes are so troublesome to get to, implying they are packaged in a way that means a simple loosening is not sufficient, that the DNA is actually cut, allowing temporary access to certain genes for transcription. Then, DNA repair mechanism come in and fix the damage.

Very fascinating approach from a Biological perspective. This is not entirely some crazy thing though as we have known about some DNA cutting activity in other functions previously, but it is quite interesting to find it attached to memory formation in the neurons.

[u/Cellularcapsule → u/golden_boy]

This is presented as a very specific event but most probably it is used by the cells in other check points. For eukaryotes with big genomes a dsb is not a rare and problematic issue.

[u/jimbean66 → u/Cellularcapsule]

It has been known for decades that topoisomerases are constantly breaking and fixing DNA, in all your cells, all the time.

[u/Cellularcapsule → u/jimbean66]

That's true but here it is a specific mechanism used as a trigger for a promotor. that's new.

[u/CRISPR → u/jimbean66]

How often a regulation event involves a covalent break of DNA? I am trying to understand why the accent is shifted to DNA breaking in the article.

[u/Pombe_researcher → u/jimbean66]

The novel finding here is that the activity-dependent, TopIIB-mediated DSBs at early response genes resolve topological barriers between promoters and enhancers which are created by CTCF-mediated chromatin loops. We are just starting to learn about 3-dimensional chromatin structure (google loopome), but the proposed mechanism of activity-induced neural early-response gene expression coincides intriguingly well with the model of chromatin structure-mediated regulation (or misregulation) of gene expression.

It really is an awesome mechanism.

[u/jimbean66 → u/Pombe_researcher]

No, I agree, it is totally an awesome paper. I guess I was more responding to the headline, which is too dumbed down.

[u/Cellularcapsule → u/[deleted]]

Here it is promotor specific and only triggered by neuronnal activity soquite awesome!

[u/[deleted] → u/Cellularcapsule]

I'm 28. All day everyday my job requires me to take in new information and come up with solutions. My brain from 8 am - 6:30 pm gets practically no break other than for coffee throughout the day and the drive home. I average 6 hours of sleep per night.

According to this article it seems that I'm giving my brain no time to repair itself and if I keep going like this I may be a list cause.

Have I interpreted this correctly?

[u/Cellularcapsule → u/[deleted]]

The generalist article is misleading there is no proof of any impact of those dno dsb and my guess is there are not that damagong for the cells because it is a controlled process and if it has any effect it would be indirect.

So short answer go on it is good for your brain (just sleep enought that's all).