Developmental perspectives on human midbrain-derived neural stem cells

"Regenerative medicine" may hopefully provide some relief or therapy for diseases which we can currently not or only barely treat. This is also true for most diseases presenting with parkinsonism, including Parkinson's disease, in spite of the available effective symptomatic treatments. The replacement of dopaminergic neurons in patients with Parkinson's disease via implantation of embryonic midbrain tissue was taken from animal experiments to clinical applications showing limited efficacy. Today, it seems possible to generate functional dopaminergic neurons from a variety of stem cells including embryonic and neural stem cells. It is not clear which tissue source will be most appropriate to test in initial clinical trials. Such cells allow for prior extensive in-vitro and in-vivo testing as well as "good manufacturing production" to reduce the risks in subsequent clinical applications.