Mice with human brain cells created at Stanford

In this article, Flayrah published that scientists want to insert human stem cells into the brains of mice. Scientists at Stanford University today announced that they have already done so. Dr. Irving Weissman of Stanford and Fred Gage of the Salk Institute of La Joya created a mouse with millions of human brain cells.Some quotes from the article:

In a cross-species experiment that raises provocative ethical questions -- but offers potential therapeutic advances -- scientists at Stanford University have created a pint-sized hybrid: a healthy mouse with paws, whiskers and millions of human cells in its brain.

The mouse acts like any other mouse, researchers say. But its brain contains a small yet significant number of injected human cells, which have taken up residence in several areas of the brain, including those that govern smell and coordination of movement.

. . .

In the experiments, started about 1 1/2 years ago by Weissman, Fred Gage of the Salk Institute of La Jolla and colleagues at Palo Alto-based StemCells, neural stem cells from 10-week-old human fetuses survived when injected into a mouse brain. Stem cells are the cells from which all others evolve.

Many of the cells continue to thrive in the brain, 14 months later.

Even more remarkably, the stem cells traveled to various regions of the mouse brain, made themselves at home there and then matured into the type of adult human cell characteristic of that region of the brain. This suggests that they respond to chemical signals in the mouse brain, instructing them how to grow up.

``Every part of the brain was populated with human cells,'' Weissman said.

Some cells traveled to the hippocampus, which has a role in emotion as well as the construction of mental maps of surroundings. Others ended up in the cerebellum, which is responsible for movement. Still others took up residency in the cerebral cortex, responsible for communication and information processing.

The mice in the experiment suffered no ill effects.