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Neurons Constantly Alter Their DNA (2015)
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Re: Neurons Constantly Alter Their DNA (2015)
#12The use of "rewrite" is a bit misleading- what's being altered in this mechanism is an epigenetic tag that sits "on top" of one of the standard DNA bases; that an individual's epigenetics are altered as they go through life is well known. But since the underlying cytosine is (as far as we know) irrevocably bound to this tag, it has to be replaced by a different (but identical) cytosine. Its more like going over your…
Actually, it's been a thing for a while that we know the brain has somatic mutations which cause the DNA to differ from cell to cell. While the epigenetic tags are also affected, it goes beyond attaching tags. The brain literally rewrites its own DNA. https://www.genomeweb.com/sequencing-technology/single-neuro...
Acquiring somatic mutations is not "rewriting its own DNA", it's just acquiring mutations. You can't replicate a piece of DNA without the chance of a mutation happening. The error rate in humans is about 1e-9 mutations/base, so by the time you've grown a brain you're likely to have a whole bunch of somatic mutations just by chance.
Re: Neurons Constantly Alter Their DNA (2015)
#13If this is the case, then we have an intersting problem. Epigenetics change, DNA - due to mutations can differ from cell to cell, people get injected with completely different DNA in the case of organ transplant. New neural pathways are created. Cells in the body are changed constantly. Memories are changed. Things like height, weight, personality traits, name, disorders, spatial location etc. can all be changed as well.
So, this raises the question of whether someone can seriously say: "I did something 15 years ago" - when many of the things that make up the human have been changed plus the person saying it is most likely making up a story about past(confabulation). What do you think?
Re: Neurons Constantly Alter Their DNA (2015)
#14This is a bit silly, eh. Every cell in your body does this kind of epigenetic modification, there are a whole host of factors whose only job is to methylate DNA. Furthermore, this is not really "altering DNA", the sequence doesn't change, this is just a way to mask gene expression - if you methylate cytosines near the promoter region of a gene, RNA polymerase has a harder time sitting down and transcribing the gene, reducing its expression.
Neurons do this, germ cells do this, immune cells do this, every cell in the body does this.
What's interesting here is the specific factor (Tet3), not the occurrence of epigenetic modification. The perils of science journalism, as usual.
Re: Neurons Constantly Alter Their DNA (2015)
#15If this is the case, then we have an intersting problem. Epigenetics change, DNA - due to mutations can differ from cell to cell, people get injected with completely different DNA in the case of organ transplant. New neural pathways are created. Cells in the body are changed constantly. Memories are changed. Things like height, weight, personality traits, name, disorders, spatial location etc. can all be changed as w…
All cells do this. It's much closer to RAM than ROM. Also, memory's are structural and much larger features than this stuff.
Re: Neurons Constantly Alter Their DNA (2015)
#16If this is the case, then we have an intersting problem. Epigenetics change, DNA - due to mutations can differ from cell to cell, people get injected with completely different DNA in the case of organ transplant. New neural pathways are created. Cells in the body are changed constantly. Memories are changed. Things like height, weight, personality traits, name, disorders, spatial location etc. can all be changed as w…
int a = 0;
a = 1;
Same variable, but the value stored changes over time.
Consider the human body to be like a variable. The value stored changes over time. When we use "I" in the present, we are talking about the "value" stored in our body in the present. When we use "I" in the past, we are talking about the value that was stored at a different time. That is how we can refer to systems that change over time using the same identifier - by treating them the same way we treat variables.
Re: Neurons Constantly Alter Their DNA (2015)
#17If this is the case, then we have an intersting problem. Epigenetics change, DNA - due to mutations can differ from cell to cell, people get injected with completely different DNA in the case of organ transplant. New neural pathways are created. Cells in the body are changed constantly. Memories are changed. Things like height, weight, personality traits, name, disorders, spatial location etc. can all be changed as w…
“No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus (supposedly)
Re: Neurons Constantly Alter Their DNA (2015)
#18If this is the case, then we have an intersting problem. Epigenetics change, DNA - due to mutations can differ from cell to cell, people get injected with completely different DNA in the case of organ transplant. New neural pathways are created. Cells in the body are changed constantly. Memories are changed. Things like height, weight, personality traits, name, disorders, spatial location etc. can all be changed as w…
> So, this raises the question of whether someone can seriously say: "I did something 15 years ago"
Only if you define "I" as something that doesn't match reality, just because people change doesn't mean they aren't still themselves. "I" doesn't refer to some ethereal unchanging thing, it merely refers to the self which is ever changing.
Re: Neurons Constantly Alter Their DNA (2015)
#19If this is the case, then we have an intersting problem. Epigenetics change, DNA - due to mutations can differ from cell to cell, people get injected with completely different DNA in the case of organ transplant. New neural pathways are created. Cells in the body are changed constantly. Memories are changed. Things like height, weight, personality traits, name, disorders, spatial location etc. can all be changed as w…
> So, this raises the question of whether someone can seriously say: "I did something 15 years ago" Only if you define "I" as something that doesn't match reality, just because people change doesn't mean they aren't still themselves. "I" doesn't refer to some ethereal unchanging thing, it merely refers to the self which is ever changing.
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Re: Neurons Constantly Alter Their DNA (2015)
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