Local production of astrocytes in the cerebral cortex

- Most astrocytes in the rodent cortex are produced early in the postnatal period.
- Four sources of astrocyte production exist in the cerebral cortex.
- Local production accounts for a major portion of astrocytes in the postnatal cortex.
- Astrocytes continue to proliferate locally in adult mice.

Astrocytes are the largest glial population in the mammalian brain. Astrocytes in the cerebral cortex are reportedly generated from four sources, namely radial glia, progenitors in the subventricular zone (SVZ progenitors), locally proliferating glia, and NG2 glia; it remains an open question, however, as to what extent these four cell types contribute to the substantial increase in astrocytes that occurs postnatally in the cerebral cortex. Here we summarize all possible sources of astrocytes and discuss their roles in this postnatal increase. In particular, we focus on astrocytes derived from local proliferation within the cortex.