Re: why nuerons dont divide? cant we make them?(at least in vitro)

Sagi,

I haven't found a specific reason why neurons stay in G₀ in culture. But I found a few references on neuronal proliferation (and what is involved in stopping it) that may be of interest:
Marques G and Fan CM, Cerebellum. 2002 Dec;1(4):259-63 - Growth arrest specific gene 1: a fuel for driving growth in the cerebellum.
Wechsler-Reya RJ, Scott MP. Neuron. 1999 Jan;22(1):103-14 - Control of neuronal precursor proliferation in the cerebellum by Sonic Hedgehog.
Hevner, Mol Neurobiol. 2006 Feb;33(1):33-50 - From radial glia to pyramidal-projection neuron: transcription factor cascades in cerebral cortex development.

But note that adult neurogenesis is observed in the olfactory stream, dentate gyrus of the hippcampus, and the cortex.
Emsley et al, Prog Neurobiol. 2005 Apr;75(5):321-41. - Adult neurogenesis and repair of the adult CNS with neural progenitors, precursors, and stem cells.

cheers,
Alex