I haven't studied neuron division to a proper extent, in fact, the references I've encountered so far point to them not dividing once they have differenciated[1], so I have to ask Gorman for a citation on this one:
But picturing the scenario of their division without problems of re-establishing their associations to the surrounding cells, I believe they could follow the process of cell memory present in the division of other specialized cells.
These methods of cell memory (positive feedback loops/faithful propagation of patterns of chromatin condensations from parent to daughter cells/patterns of DNA methylation) ensure that daughter cells "remember" what kind of cells they are supposed to be, and coupled with fidelity in DNA replication (as explained by hanz0 and his previous post) from what I know I assume that new cells would be identical in such a way that with a strict control of their division you wouldn't have the identity problems you proposed.



Just to add to hanz0's explanation of our "mutation tolerance", you also have some redundancy on the genetic code that makes possible for mutations on the really important parts of our genes*, so to say, to don't cause anything wrong.
Considering how the portion of our genome that actually codes proteins is only 1.5% though, hanz0's examples were indeed more significant.


*exons, as opposed to the introns hanz0 referred
[1]"Some highly specialized cells never divide again once they have differentiated; for example, skeletal muscle cells and neurons." from http://books.google.pt/books/about/E...AJ&redir_esc=y (I don't think I can direct you the exact file of the book because of "issues" but if you manage to get your hands on the 3rd edition, it's on page 287)

Could not find citation, but I read a lot of articles and turns out although they can divide they generally don't, the vast majority are formed before birth and survive without dividing till death. Only the minority divide.

I think there must be a higher order mechanism for dealing with neuron replacement, if you take neuroplasticity in to consideration. How could this be possible if a direct ancestry is required?

Neuroscience probably isn't very simple...

I wasn't suggesting that maintenance of identity required direct ancestry, only that direct ancestry could maintain identity.

For the rewiring proposed in neuroplasticity, I'm guessing synaptogenesis without necessarily resorting to neurogenesis could also help so you'd have a replacement of neuronal function and remapping without having to necessarily "create" more neurons. (this doesn't mean I'm arguing about the existence or not of neurogenesis, after your last post I went on searching for more information and found what you did)

Though I agree with you, if neuron replacement was as simple as direct ancestry we (meaning you and me who went on discussing it) probably would have found that information somewhere already because it'd mean that the mechanism would be simple enough.

The course of study of my degree only has neuroscience 2 semesters from the one I am on right now though, so like I said, I haven't actually studied the subject properly and I'm merely making slightly educated guesses

Just because this relates to this topic, I'm constantly hearing more and more about how stuffing yourself with vitamins and such helps you live "healthier" as well as "longer". Is that necessarily true? I mean I know a few people who rarely take ANY vitamins at all and they are currently 80 years old which seems pretty long to me, and yet all their doctors tell them they are healthy. So do vitamins like in pill form really do more than just making sure you get the proper amounts in your meals each day?

Think of it this way, you should have a certain amount of each micro nutrient, and if you have less you become unhealthy (or are at risk of), if you eat more then it is usually just excreted. So if you are getting enough calcium (for example) out of your food, you don't need a supplement, and if you do take one it won't do anything. However if you don't get enough then your bones become weak, and bad things can happen - then again nothing bad might happen, because it's the risk that increases, it's not certain.

Eating a balanced and healthy diet keeps you healthy, so you are less likely to develop all kinds of bad things, from scurvy to osteoporosis.
However none of these things will increase life span, they will just increase life expectancy. Life span is how long a person lives before dieing of "old age", where as life expectancy includes all other causes, from car accidents to obesity. In this situation, obesity could be prevented by eating health amounts of macro nutrients.

Vitamins are not magic, they don't increase your life span. They do help protect you from all kinds of deficiencies - but you may have heard people refer to them as "expensive urine", as most people get enough from their diet anyway.

Mostly it just makes your urine alot more expensive than usual.

Kind of figured that. Well at least I got an answer to my question so thanks.

I'm going to tell you the same thing I told scorpionma: Unless you are capable of providing an intelligent argument, get out and let the big boys talk.

Further idiotic posts will be infracted at my discretion.

Human life spans keep getting longer and longer... On the other side, for now, eating and doing healthy stuff will help you live longer.

this is scientifically true but there is always that one old crow who smokes and drinks who manages to out live every one.