Scientists in the US have successfully made human being brain cells in the lab that are a correct copy of hereditarily caused Parkinson's disease. To make the human neurons the scientists used a technique already successfully tested by others which can turn donated skin cells into brain tissue.
They used skin samples from four volunteers - two healthy people and two with Parkinson's disease caused by a parkin gene mutation. Studying human neurons is critical in Parkinson's disease since animal models that lack the parkin gene do not develop the condition, rendering them useless for this research purpose. They have already shown that they can reverse the defect by putting a normal parkin gene into diseased neurons.