Stem cell therapy for Parkinson's restores dopamine in rats

Researchers have reversed the effects of Parkinson's disease in rats, by using human embryonic stem cells.

Parkinson's disease is caused by the gradual loss of nerve cells in the brain that produce dopamine, a chemical that assists in controlling movement and mood. There is no cure, although medication and deep-brain stimulation can alleviate symptoms in some patients.

Lead researcher Professor Malin Parmar told the BBC: 'It's a huge breakthrough in the field [and] a stepping stone towards clinical trials.'

To create a model of Parkinson's in rats, the research team from Lund University in Sweden destroyed the dopamine-producing cells in one part of the rat's brain. They then transplanted dopamine cells made from human embryonic stem cells into the rats' brains. Once complete, the researchers found the transplanted cells behaved like natural, native dopamine cells. As a result, the rats regained normal motor function.

Professor Parmar said: 'This study shows that we can now produce fully functioning dopamine neurons from stem cells. These cells have the same ability as the brain's normal dopamine cells to not only reach but also to connect to their target area over longer distances.'

Arthur Roach, the head of research and development at the charity Parkinson's UK hailed the study as an important step in 'helping us to understand how stem cells might shape future Parkinson's treatments'. However, Roach cautions that using this technique in humans is still a long way off: 'This study could be a stride towards clinical trials in people with Parkinson's but there are still many questions that need to be answered before this development can be tested in people with the condition.'

The Lund team expect human clinical trials to begin within three years.

The study was published in the journal Cell Stem Cell.