Dopamine neurons derived from stem cells and inserted into a monkey's brain reduce Parkinson's-like symptoms over two years.

Ole Isacson at Harvard Medical School in Boston, Massachusetts, and his colleagues created dopamine-producing midbrain neurons using induced pluripotent stem cells derived from the skin of cynomolgus monkeys (Macaca fascicularis). These neurons were introduced into the brains of three monkeys that lacked dopamine neurons — a model for Parkinson's disease, in which monkeys have impaired motor skills and are less active than normal monkeys.

In the most successfully treated animal, the stem-cell-generated neurons survived and grew axons, and dopamine production was restored. This animal gradually improved during the two years after treatment and showed normal activity, suggesting that transplantation of stem-cell-derived neurons could one day treat Parkinson's disease.

Cell Stem Cell http://doi.org/2gm (2015)