[Perspective] Differences among astrocytes
Astrocytes are diverse in morphology and molecular makeup (1, 2), potentially enabling them to provide for the varying needs of their diverse neuronal counterparts (3). What accounts for and maintains astrocyte heterogeneity are only beginning to be explored. One possibility is that the signals specifying astrocyte subpopulations might operate only during the critical phases of development, after which the cell is hardwired. Alternatively, these signals might be operational at all times. On page 849 of this issue, Farmer et al. (4) reveal that neuronal signals drive the molecular programs of astrocytes even during adult stages of life. This challenges the idea that astrocyte function is hardwired during development and provides a new mechanism for cellular plasticity in the adult brain. Authors: Beth Stevens, Allie K. Muthukumar