Oligodendroglial heterogeneity in time and space (NG2 glia in the CNS)

NG2 glia represent a neural cell population that expresses the proteoglycan NG2 and is distinct from other cell types of the central nervous system. While they generate oligodendrocytes and a subset of astrocytes during development, their progeny in the adult brain solely consists of oligodendrocytes and further NG2 glia. In the last years, it has become clear that NG2 glia represent a heterogeneous population of cells with different properties and potential. In this review we will first discuss the similarities and differences between NG2 glia of the developing and adult CNS, before we will describe the regulatory mechanisms in these cells to finally concentrate on the heterogeneity of NG2 glia under physiological and pathological conditions.