Just two weeks after a previous similar reporting, Cambridge scientists have reported that they successfully used stem cells that were "reprogrammed" from ordinary skin cells to alleviate symptoms of Parkinson's disease in rats. Their work was published in the Proceedings of the National Academy of Sciences and shows that reprogrammed cells, also called induced pluripotent stem (iPS) cells, can become functioning neurons when transplanted into the brains of mice and rats.

The team, which was made up by scientists from MIT and Harvard, has transplanted healthy neurons cultivated from reprogrammed stem cells into the midbrains of rats which were previously damaged similarly to the effects of Parkinson's. The rodents showed significant alleviation of symptoms of brain damage, such as wandering in uncontrollable circles.

"This is the first demonstration that reprogrammed cells can integrate into the neural system or positively affect neurodegenerative disease," said Marius Wernig, a scientist at the Whitehead Institute for Biomedical Research and lead author of the research, quoted by The Boston Globe.

This approach to obtaining stem cells, the so-called nuclear reprogramming technique, is much more interesting in the long term and has gained momentum recently. While "therapeutic" cloning produces stem cells, the technology involves the creation and destruction of embryos, which is ethically unsound. The stem cells created also run the high risk of being rejected by the recipient's body. In turn, nuclear reprogramming, creates stem-like cells from the patient's own cells, avoiding both medical and ethical problems. Dolly's cloner, Sir Ian Wilmut, also endorsed this technique and declared last year he abandoned the idea of human cloning in favor of nuclear reprogramming.

Two weeks ago, American and Japanese researchers converted skin cells from the tail of the sick animal into the dopamine-producing brain cells they lacked, and grafted the genetically matched tissue back into the same mice. Before being injected with the stem cells, the mice had a number of behaviors common to their disease. Once injected with the cells, mice’s behavior returned to normal. It was after the mice were killed, when the researchers discovered that the neural cells they’d injected had grown and formed connections with other cells.

There's also a downside to Parkinson's treatments using stem cells: recent studies show that treatment solutions for Parkinson’s disease must be much improved because some traces of brain damage linked to the disease were found spreading into the transplanted tissue. This suggests that the disease presents an ongoing process which constantly inflicts damage.