Scientists reported successful treatment of the rat version of Parkinson's disease using embryonic stem cells back in April of this year.

The Israeli team treated human stem cells in the laboratory. They then transplanted them into the brains of rats which had a Parkinson's-like condition. The rats' behaviour changed after their treatment. Before it took place, they would turn continually, and would be unable to make side steps while they were being dragged across a surface. But after the transplants, these symptoms were significantly reduced. When post-mortem examinations were carried out on the rats, it was found that the stem cells had developed into dopamine-producing cells.

Betterhumans noted today that similar work now has been accomplished in monkeys:

Takahashi and colleagues had previously shown that mouse embryonic stem cells can differentiate into neurons when cultured under specific conditions. The same culture approach - considered technically simple and efficient - was also recently shown to work in primate embryonic stem cells.

For the new study, Takahashi and colleagues generated neurons from monkey embryonic stem cells and exposed them to a growth factor called FGF20. The growth factor is produced exclusively in the part of the brain affected by Parkinson's disease and is reported to help protect dopamine-producing neurons.

The growth factor increased the development of dopamine-producing neurons, which the researchers then transplanted into monkeys with a primate model of Parkinson's disease. They found that the transplanted cells functioned as dopamine-producing neurons and lessened Parkinson's symptoms.

A few years ago, many observers - myself included - suspected that Parkinson's treatments would be one of the first widely available first generation regenerative therapies based on stem cells. That may still be the case, unless therapies for paralysis and heart disease arrive first. It is interesting to note that the varied therapies attracting the most attention and funding at the moment are all quite different in their approach and utilization of stem cells. This is a very positive sign.