axon regeneration as part of differentiation?

[Marc Gillespie]

Hi All,

I am sure this will only muddy the water, but here are my thoughts  
below.

Marc

Marc Gillespie
Reactome
Stein Lab
Cold Spring Harbor Laboratory
1 Bungtown Road
Cold Spring Harbor, NY 11724

email: gillespm at cshl.org
telephone: (718) 990-5249

http://www.reactome.org


On Oct 26, 2005, at 2:53 PM, Doug Howe wrote:

> I wanted to see if anyone else in the Neuro interest group thought  
> there was an issue here before I posted a SF tracker item on it.
> The term GO:0031103 'axon regeneration' has 'neuron morphogenesis  
> during differentiation' in it's path to root. This means that the  
> process of 'axon regeneration' in GO is implicitly restricted to  
> occur during neuron differentiation.   This doesn't seem correct to  
> me.  It seems to me that 'axon regeneration' is the extenstion of  
> an axon by a mature neuron (ie not a differentiating neuron) after  
> loss of the axon for some reason.

Depends on what happens at the molecular level, which I am interested  
to find out if we know one way or the other. Does regeneration  
involve the same process, albeit locally within the axon, that would  
be occurring during the original differentiation? Somehow I remember  
way back when reading that in some peripheral cases schwann cells act  
as a guide, but there is no guarantee that the axon will return to  
its previous precise location, and that the growing axon repeats the  
process that occurred in differentiation, though now, because of  
physical constraints it has a limited number of choices.

> This process doesn't involve de-differentiation and re- 
> differentiation of the neuron.

Isn't the fact that it is an extending axon, a form of "de- 
differentiation? Differentiated axons don't extend?

>
> Does anyone else see it that way?

I have to say though that I see what you are saying as well. What do  
we do with the observation that the soma of the cell is probably not  
undergoing all of the changes that are involved in 'neuron  
morphogenesis during differentiation'?

Maybe the root of the question; Is it ok for  'neuron morphogenesis  
during differentiation' to refer to just the axon of a neuron?


>
> I'm not in tune with the current biology on this, so I could be  
> incorrect.
>
> -Doug
>
> -- 
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