neuroblast vs. neuronal progenitor

[Nicolas Le Novère]

The point is, as far as I know, there is no cell able to become any neuron
but not a glial cell. This is hard to believe considering the molecular
similarity between neuron, but it seems that in every nervous structure
the progenitors can become either glial cells or neuronal cells. And from
my experimental time, I can tell you it is nor hard to cultivate
neuroblasts and direct them in one way or the other.

Therefore, we are facing a nomenclature dilemna, as taxonomists often
face. The common usage is the paraphyletic name (neuroblast). We can use
it for the ancestor of the whole clade: Neuroblasts would be the
progenitors of neuronal cells or glial cells. Taxonomists kind of did that
with reptilia. The clade encompasses anapsida (turtles) and diapsida
(crocodils, lizards and ... birds [sorry, dinosauria]). It is very
confusing for non-specialist (birds are reptils ...)

Or we can use indeed the term neuroglial  progenitor. In that case, we
should avoid the term "neuroblast" for the cell giving birth only to
neurons. We should have one term per type of neuron, such as "cortical
neuron progenitor" (or even "cortical pyramidal neuron progenitor". To be
determined by actual specialists, not amateurs like myself)

> In this case, I think I will delay any action along these lines until it
> can be given the proper attention it deserves.  This is a complex issue
> fraught with developmental timing issue which we should try to avoid...
>
> I guess the crux of the issue to figure out is whether or not all three
> of the following exist and what they might be called:
> 1.  a relatively unspecialized cell that is only capable of becoming a
> neuron of one type or another (neuroblast? neuronal progenitor?)
> 2.  a relatively unspecialized cell that is only capable of becoming a
> glial cell of one type or another (glioblast? glial progenitor?)
> 3.  a relatively unspecialized cell that is only capable of becoming
> either a neuron or glial cell of one type or another (neuroblast?
> neuron-glial progenitor?)
>
> -Doug
>
>
> Nicolas Le Novère wrote:
>> I am not entirely sure about that (mostly because I'm writting that
>> looking at telly during an advert break in the middle of Farenheit 9/11.
>> Pretty hard to concentrate on anything else), but I think neuroblasts
>> are
>> definitely progenitors of both neurons AND glial cells. I.e. neuronal
>> precursors form a paraontogenic group (based on paraphyletic). I am
>> almost
>> sure of that for Bergman glia.
>>
>>
>>> Would everyone agree if I were to suggest that all GO terms that have
>>> "neuroblast" in the term name also have an exact synonym using the term
>>> "neuronal progenitor"?
>>>
>>> Eg.
>>> "neuroblast differentiation" would get an exact synonym of "neuronal
>>> progenitor differentiation".
>>>
>>> Likewise, I would like to suggest a new term on SourceForge for
>>> "glioblast differentiation" with the exactly synonym "glial progenitor
>>> differentiation".
>>>
>>> I realize that sometimes a single cells can pass through a stage during
>>> which it is a progenitor capable of generating neurons and glia in some
>>> cases..but I think this is OK..maybe we could even have a term like
>>> "neuro-glial progenitor differentiation" to represent differentiation
>>> of
>>> this type of cell?
>>>
>>> What do you think?
>>>
>>> -Doug
>>>
>>>
>>
>>
>>
>
>


-- 
Nicolas LE NOVÈRE,  Computational Neurobiology,
EMBL-EBI, Wellcome-Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
Tel: +44(0)1223 494 521,  Fax: +44(0)1223 494 468,  Mob: +33(0)689218676
http://www.ebi.ac.uk/~lenov