Mosaic organization of neural stem cells in the adult brain.

The in vivo potential of neural stem cells in the postnatal mouse brain is not known, but because they produce many different types of neurons, they must be either very versatile or very diverse. By specifically targeting stem cells and following their progeny in vivo, we showed that postnatal stem cells in different regions produce different types of neurons, even when heterotopically grafted or grown in culture. This suggests that rather than being plastic and homogeneous, neural stem cells are a restricted and diverse population of progenitors.