Thread: Does some atoms in our bodies stay until we die?

I've heard from Richard Dawkins (While he quotes someone else that I don't remember, think it's from one of his TED talks) that all the atoms in our bodies are swapped over our lifetime. I've also heard the cycle takes 7 years for every atom to have changed.

But I've also heard that parts of our brain stays the same forever.


If it IS true that parts of our brains stay. Is that the same atoms that keep memories? Or is it true that somehow the new atoms 'learn' the post-7 year old memories? Because that would be really cool ^^

Originally Posted by Venerable

I've heard from Richard Dawkins (While he quotes someone else that I don't remember, think it's from one of his TED talks) that all the atoms in our bodies are swapped over our lifetime. I've also heard the cycle takes 7 years for every atom to have changed.

But I've also heard that parts of our brain stays the same forever.


If it IS true that parts of our brains stay. Is that the same atoms that keep memories? Or is it true that somehow the new atoms 'learn' the post-7 year old memories? Because that would be really cool ^^

Any given cell may hypothetically change out all of it's constituent atoms and still be the same cell. So it is possible to have the same set of brain cells for life, even if the atoms that form those cells turn over in some staggered manner once every 7 years.

I don't actually know whether this is what happens, I'm just saying that one assertion does not contradict the other.

There's also no real reason to assume this has anything to do with memory. Besides, memories are similarly fluid. I think I have memories dating back to 1982, but in reality these are probably copies of copies of an original memory. Probably heavily modified by my own personal biases and my dear mother's retelling of the events concerned from her perspective.

Bear in mind that memory is actually just electric potential of different atoms in cells. So if it is an original memory, and not an transcript, then the atoms are same. I guess there is no real way of determining whether there is some exchange of atoms in brain cells, however, if there is, it is certainly much slower than in other body parts...

Originally Posted by Sindrato

Bear in mind that memory is actually just electric potential of different atoms in cells.

How do you know this?

I'm not actually sure, but I do have a felling that my teacher mentioned it a few times...

Originally Posted by Sindrato

I'm not actually sure, but I do have a felling that my teacher mentioned it a few times...

Never heard of the idea, not that I'm an expert on memory. To be honest, even if memory were based on something like electric potential, that would still not imply that atomic/molecular turnover in the cells would be any slower than elsewhere in the body, would it?

A little bit of research suggests to me that long term potentiation is thought to be the process that underlies long term memory formation.

I apologize if I'm wrong. I actually quite often simply believe what my teachers say, sometimes forgetting that they actually aren't experts in their fields, that most of them don't even like their job, and that they most often don't follow new research. Thanks for the information, anyway.

Originally Posted by Sindrato

I apologize if I'm wrong.

You don't need to apologize- being wrong is nothing to be ashamed of. Besides, it's very possible that I'm totally off the mark anyway- brain stuff is pretty far outside of my own expertise. Though I have collaborated on a little bit of neuroscience research in the past, I left the brain stuff to the psychologists.

during dna replication you have the original set of dna which splits into two chains, and then you have new chains forming onto the half chains.

the new chains contain the old chains, and thus the old atoms. there are processes to fix replication errors but a large part of the dna doesn't have said errors and the atoms are the same ones that the parent cells had.

i find it highly unlikely that not a single atom from the dna of the sperm and egg would survive in the dna of the fully formed person. of course, the original atoms in the dna would be heavily diluted due to all the replication that goes on before a child is even born.

Of course Saul, but we were talking about atoms of nerve cells, and as you surely know, brain cells do not replicate.

Originally Posted by Sindrato

Of course Saul, but we were talking about atoms of nerve cells, and as you surely know, brain cells do not replicate.

That would be a false statement.

Some do.

Apologies, nerve cells do not replicate.

they do. Just not everywhere in the brain.

Are you sure. I mean, I am not an expert, but we were taught that they don't. Can you provide some info?

It's not really that new information. The first surge of information came around 1998.

But actually there have been articles from the 50 or 60s (can't remember) which showed regeneration in the same areas but they were dismissed.


popular science summary.
http://www.newscientist.com/article/...lt-humans.html

Thanks for the link. It was helpful. However, what is described there isn't actually replication of brain cells, but rather development from steam cells.