Scientists at the Buck Institute in California have produced human induced pluripotent stem cells (iPS cells) and used them to improve the condition of a rat model of Parkinson's disease. The human iPS cells were made using samples of normal cells from skin and blood, and then a four-step procedure used to specialize the cells into dopaminergic neurons, the type of neurons missing or damaged in Parkinson's disease. Approximately 30% of the cells formed the desired neurons. When injected into rats that are a model of the disease, there was some improvement in the rats over a 12-week period. A previous study by MIT researchers used mouse iPS cells to improve a rat Parkinson model.

Senior author of the study published in the journal Stem Cells, Dr. Xianmin Zeng, said:

"Human iPSCs may provide an end-run around immuno-rejection issues surrounding the use of human embryonic stem cells (hESCs) to treat disease. They may also solve bioethical issues surrounding hESCs."

Adult stem cells have already shown success at treating Parkinson's disease including adult stem cells from endometrial tissue and from nasal tissue, and a Parkinsons patients own neural adult stem cells ameliorated his symptoms for almost five years.