Nerve cell and mitosis?

Question

I know nerve cells can't under go mitosis but why cant they? What stops them from doing it

Answer 1

Technically nerve cells can still undergo mitosis after they've fully differentiated; they normally don't just because of the kinds of regulatory proteins they express on reaching maturity. These regulatory proteins bind to the neuron's DNA and prevent it from duplicating itself, but the cell still has the ability to do it. Many cancers and tumors that occur in the brain, for example, are nerve cells that have lost one or more of their regulatory proteins (due to a mutation, or some other defect). They then reproduce uncontrollably.

I'm not sure why the nerve cells express these sorts of repressor regulatory proteins, but its likely a mechanism to avoid tumor development. The brain is especially susceptible to tumors because it is not as heavily regulated by our immune systems as our other organs are (and it is the immune system that stops most tumors before they get out of control).

Answer 2

Nerve Cell Mitosis

Answer 3

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RE:
Nerve cell and mitosis?
I know nerve cells can't under go mitosis but why cant they? What stops them from doing it

Answer 4

First of all, your initial claim is wrong. Nerve cells DO undergo mitosis. This is, in fact, a fairly recent discovery.

It used to be thought that all people produce the huge mass of neural tissue that is their brains and nervous system when they are young and then that's it. Recent studies have shown that this is not so. In fact, just as with most of the rest of your body, new cells are constantly being produced and added to your existing system to replace cells that die, repair damage, and so on.

Now, ALL your neural cells are not doing this, but then this is true also of almost all the tissues in your body. Most tissues have a section of 'immature' reproducing cells. Some of the 'daughters' of these cells then mature and become regular tissue, while some remain as part of the rapidly dividing region. So in this sense nerve cells aren't much different from most of your cells. Most cells do not undergo mitosis much, if at all, when they are adults.

As to how exactly that works, it has a lot to do with DNA transcription. If you think about it, each cell has all the DNA necessary to be any kind of cell. Liver cells have the DNA to produce hormones that are only supposed to be found in the brain, your brain cells have the DNA needed to produce food-digesting enzymes, and so on and so on. Can you imagine the chaos that would ensue if all these cells actually MADE all that stuff?!

Instead, most of those sections of DNA are 'turned off' by various means. Kind of like a computer code, each gene starts with a section of DNA that is just a marker... sort of a "the gene starts here!" sign. One example of a way genes are turned off is just by 'covering up' that sign. As you can imagine from the implications above, most genes in most adult cells are, in fact, completely off.

This is why genetic engineers like to find and use 'stem cells'. Stem cells are the 'immature' cells that can divide and turn into other things. Adults have them spread throughout most of their body in small amounts, to produce new tissue and stuff. Stem cells don't have anywhere near as much of their DNA turned off. The 'ideal' stem cell is one that can turn into ANY cell and has NONE of it's DNA turned off. These are generally only found in early embryos, before any substantial tissues have been formed at all. Though scientists are also working on ways to be able to turn genes back on so other stem cells and perhaps even adult cells can be made more useful for more things.

Hope that helps! Biology is fascinating!

Answer 5

mitosis occurs in all body cells, the only cells it doesn't occur in is sex cells, were meiosis occurs.