Stem cell transplantation is a promising avenue of research into new treatments for Parkinson's disease. But such research has been held up by the limited supply of these cells. According to a new report, this logjam may soon be over -- US researchers have successfully cultured mouse stem cells in the lab.

Researchers in Bethesda, Maryland, have now been able to generate new neurons in a petri dish using embryonic stem cells from mice, explained Nadya Lumelsky, one of the authors of the study published in the June issue of Nature Biotechnology. ``We achieved the kind of neurons that are necessary,'' Lumelsky told Reuters in an interview.

In an adjunct to this exciting finding, investigators elsewhere in the United States have recently developed human embryonic stem cell lines, so the possibility of replicating this finding in humans is feasible, Lumelsky said. She noted the human cell line is not available for research at this time.

The research team hopes that their findings may lead to an endless supply of these cells. Stem cells can be manipulated to eliminate unwanted features, such as deleting an immune response in people who have received a transplant and might otherwise reject a new organ, she explained.

``We can actually force them (stem cells) to become the cells we want them to be,'' Lumelsky said. Not only could the generation and manipulation of stem calls be invaluable in assisting patients with neurological diseases such as Parkinson's or multiple sclerosis, but the good they could do is ``not defined to diseases of the nervous system,'' Lumelsky added. ``It's a potential approach to many diseases.''

The research is very new, she noted. Investigators need to continue to test this approach in animal systems and then test the viability of these cells. ``We want to create a so-called 'brain in a dish,''' Lumelsky stated.

When they started their research, the scientists hoped to be able to generate cells for the treatment of Parkinson's from sources easily available. In the past, other researchers have generated nerve cells, but these were using cells from fetuses, Lumelsky said.

Fetal cells are not readily available, and the use of these cells raises ethical concerns, she noted. With this research, it is shown that embryonic stem cells, at least those from mice, can be regenerated, and if replicated in humans, there would be an endless supply, she suggested.

``These are historical times. There is the realization that we can control cell fate using growth factor and other biological molecules,'' Lumelsky said. ``It's an important transition step. It's like learning how to fly.''