REVIEW ARTICLE NG2 Cells (Polydendrocytes): Listeners to the Neural Network with Diverse Properties

NG2 cells (polydendrocytes) are the fourth major non-neuronal cell type in the central nervous system parenchyma. They exhibit diverse properties, ranging from their well-established role as oligodendrocyte precursors to their ability to respond to neurotransmitters released by synaptic and non-synaptic mechanisms. The functional diversity of NG2 cells has prompted the question of whether they represent a single cellular entity or multiple distinct cell populations. This review first summa-rizes recent findings on the nature and mechanism underlying the diversity of NG2 cells with regard to their proliferative and differentiation behavior. This will be followed by a synopsis of observations on how their microenvironment, particularly neu-ronal activity, influences their dynamic behavior, and how these changes in NG2 cells could in turn influence neural function and animal behavior. GLIA 2014;62:1195–121