In vitro expansion of central nervous system (CNS) precursors
might overcome the limited availability of dopaminergic neurons in transplantation
for Parkinson's disease, but generating dopaminergic neurons from in vitro
dividing precursors has proven difficult. Here a three-dimensional cell
differentiation system was used to convert precursor cells derived from E12
rat ventral mesencephalon into dopaminergic neurons. We demonstrate that CNS
precursor cell populations expanded in vitro can efficiently differentiate
into dopaminergic neurons, survive intrastriatal transplantation and induce
functional recovery in hemiparkinsonian rats. The numerical expansion of primary
CNS precursor cells is a new approach that could improve both the ethical
and the technical outlook for the use of human fetal tissue in clinical transplantation.
