After birth neurons generally do not divide. But is there any specific type of rare cancer or tumour where neurons divide? And if there is such a cancer, then how is it possible for a neuron to regain the division power?
I think that most mature cells do not divide in all tissues. If organism need to repair tissues, it uses tissue cell precursors -- stem cells.
In case of neurons, these are neuroblasts. Neuroblasts can divide and can repair brains under some circumstances (I don't know under which).
There is a cancer grown from neuroblasts, called neuroblastoma.
I think it is very unprobable to have tumor from neurons, because division gens are turned of in mature cells. Can't state it is not occurring in practice.