Breakthroughs in stem-cell research raise hopes for Parkinson's cure

Scientists have hailed a dual success in the fight for a cure for degenerative brain diseases such as Parkinson's.

In the first breakthrough, researchers transformed embryonic stem cells into neurons in the laboratory, and then transplanted them into rats with Parkinson's disease. The "spare part" tissue formed functional nerve connections, producing the essential brain chemical dopamine – which Parkinson's sufferers lack – and reduced symptoms of the disease, said the scientists from the National Institute of Neurological Disorders and Stroke, in Bethesda, Maryland.

Another team, led by Catherine Verfaillie at the University of Minnesota, Minneapolis, showed how a type of adult stem cell might be as versatile as embryonic stem cells. The discovery could help to circumvent many of the ethical objections to stem-cell research, which otherwise involves embryos that have to be destroyed after five days.

Stem cells are unprogrammed "mother" cells that can change into different kinds of tissue. They are abundant in early-stage embryos, have the potential to become any part of the human body and can be grown in the laboratory.

Adult stem cells had been generally thought to have much more limited scope, although many believe it is ethically more desirable to use them than stem cells extracted from five-day-old embryos.

Both studies were published in the online version of the journal Nature and were hailed as landmarks by British scientists. Professor Tom Kirkwood of the Department of Gerontology at Newcastle University, said: "These are very exciting reports. We really need to understand just how versatile adult stem cells can be, and whether embryonic or adult stem cells can transform correctly when put into adult tissue, particularly the damaged tissue found in diseases such as Parkinson's disease."

Professor Richard Gardner from Oxford University, who chairs the Royal Society committee on stem-cell research, said it was impossible to decide whether adult or embryo stem cells would be best for treating disease. "For the moment, we must pursue both lines of research, " he said.