THEY look like mouse brain cells, they behave like mouse brain cells, yet they came originally from a human embryo. When human embryonic stem cells (ESCs) were injected into the brains of two-week-old mouse fetuses, they developed and functioned like normal mouse cells. They were not rejected by the mouse’s immune system, and even grew to the same size as mouse cells.
The finding that human ESCs can fit in so well in their new home is encouraging news for researchers hoping to use them to treat neurological diseases. It also lessens ethical concerns about inadvertently creating animals with part-human…
