From EurekAlert!, a taste of the groundwork presently taking place: "To determine whether stem cell biology might play a role in benefiting [neurodegenerative] diseases, the investigators [used] mouse neural stem cells (NSCs), a type of "adult" stem cell, to establish the parameters of what might or might not be achievable in this disease. Then, having demonstrated success with mouse cells, they extended those insights to stem cells of human origin, both human neural stem cells and human embryonic stem cells ... The results [in fact] prove to be the first successful use of human embryonic stem cells in treating a degenerative disease, significantly preserving function and extending life. ... implanted neural stem cells, which migrated and integrated extensively throughout the brain, did much more than replace brain tissue destroyed by the disease. Some of the transplanted cells replaced damaged nerve cells and transmitted nerve impulses, offering the first evidence that stem cell-derived nerve cells may integrate electrically and functionally into a diseased brain. ... [the] treatment also dampened the inflammation that typically occurs in the brains of most degenerative diseases."