Neural stem cells exist in the mammalian developing and adult nervous
system during the neural differentiation of the embryonic stem cells. Stem cells are
important cells for replacement therapy diseases. The interest in the potential of for
the treatment of neurodegenerative diseases and brain injuries has substantially
promoted research on neural stem cell self-renewal and differentiation. General
chapters of this review will deal with the history and origin of, their properties and
characteristics that distinguish from other cells, the classification, and biological
disorders causing neurodegenerative diseases. The literature, data and arguments that
are dealing with, how the differentiate into neural cells, and how could this process
can be handled in vitro are reviewed. The unique capability of these cells to form
various tissues under definite signals received from the body, it makes this cell an
object of extensive research. Subsequently, information has been compiled on the
question how neural differentiation is controlled on the molecular level, and
controlled in vivo. Finally one major gene involved will be investigated, which are
may be investigated in practical pirogue according there expression patterns. And this
gene is tyrosine hydroxylase.
Keywords: Stem cells, Neural stem cells, Embryonic stem cells, Tyrosine
hydroxylase, Parkinson's disease