Grafting dopamine neurons in Parkinson's disease: do stem cells have a role in the future?

Parkinson's disease (PD) patients display motor symptoms, e.g. tremor, rigidity and bradykinesia, largely due to a dramatic loss of dopaminergic neurons in the substantia nigra. Grafts of human embryonic dopamine neurons can survive in the striatum and reduce several of the motor symptoms. Several lines of evidence suggest that a crucial threshold of surviving dopaminergic neurons must be exceeded for the grafts to become functional and relieve symptoms. A relatively small number of operations have been performed so far. The major obstacle to large clinical trials has been that tissue from large numbers of donor embryos is needed for each patient. Thus, there is definitely a need for alternative sources of donor tissue for grafting in PD. Clearly various forms of stem cells are interesting options. This presentation will focus the possible future use of embryonic stem cells and bone marrow stem cells as donor tissue for transplantation in PD.