New research raises the hope that cells, like organs, could one day be taken from the dead and given to the living. Fred Gage, of the Salk Institute, and colleagues have cultured neural progenitor cells -- which can go on to divide into nerve cells -- from cadaver brains1. This could offer another, less ethically fraught alternative to fetal cells as a source of human replacement tissues.

The full medical potential of this finding is still unclear. The post-mortem cells do not divide as much as those from fetal tissue, for example, and the various types of cells they can form remain to be discovered.

"These results confirm that the adult human brain contains cells that can continue to divide and differentiate," says Gage. As well as for use in transplants, he says, this finding may eventually enable us to reactivate cells in the brains of living patients. This could lead to treatments for diseases such as Alzheimer's and Parkinson's where nerve cells are lost.

Gage and his colleagues kept the cells functioning for many months; they can also be frozen for later use. Gage thinks progenitor cells for other tissues could probably be taken from people after death. But, he adds, "the age of the donor and the time after death are important".