Scientists use nerve cells to grow other tissues

A team of Swedish researchers has found that adult mouse nerve cells transplanted into embryos are able to grow into a variety of different tissues, including heart, liver, muscle and intestine. Their findings, published in last week's Science, suggest that specialised adult stem cells - cells that grow into certain types of body tissue, for example skin, nerves and muscle - may be more versatile than previously believed.

The scientists, based at the Karolinska Institute in Stockholm, took adult mouse nerve stem cells and placed them in either mouse embryos, or cultured mouse embryo cells. They found that the fate of the transplanted cells depended on the type of cells surrounding them.

Co-author Jonas Frisen admitted he had 'no clue' about the role of the cellular environment in determining the fate of the transplanted cells. 'There is probably a cocktail of various factors involved, but we have no solid data yet about what these molecules are' he said. If scientists can identify these chemical signals, it may be possible to use adult human stem cells for growing new tissues outside the body.

Reports in both the UK and US newspapers were quick to point out that the new study offered an alternative to human 'therapeutic cloning' - the use of cloned embryo stem cells to grow new body tissues. Dr Frisen said the use of stem cells taken from an adult was a tantalising possibility, but cautioned that 'we need to be open and pursue research in all fields until we really know which will be most valuable'.