New roles for astrocytes : The nightlife of an ‘astrocyte’. La vida loca !

Like a newly popular nightspot, the biology of adult stem cells has emerged from obscurity to become one of the most lively new disciplines of the decade. The neurosciences have not escaped this trendy pastime and, from amid the noise and excitement, the astrocyte emerges as a beguiling companion to the adult neural stem cell. A once receding partner to neurons and oligodendrocytes, the astrocyte even takes on an alter ego of the stem cell itself (S. Goldman, this issue of TINS ). Putting ego aside, the ‘astrocyte’ is also (and perhaps more importantly) an integral component of neural progenitor hotspots, where the craziness or ‘ la vida loca’ of the nightlife might not be so wild when compared with our traditional understanding of the astrocyte. Here, astrocytes contribute to the instructive confluence of location, atmosphere and cellular neighbors that define the daily ‘ vida local ’ or everyday local life of an adult stem cell. This review discusses astrocytes as influential components in the local stem cell niche.