NG2 cells (polydendrocytes): Listeners to the neural network with diverse properties

Abstract

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 summarizes 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 neuronal activity, influences their dynamic behavior, and how these changes in NG2 cells could in turn influence neural function and animal behavior. GLIA 2014;62:1195–1210

Differential expression of the calcium-sensing receptor in the ischemic and border zones after transient focal cerebral ischemia in rats

“…However, specific immunochemical markers for pericytes are lacking (Fisher, 2009), and NG2 chondroitin sulfate proteoglycan has been reported to be expressed in diverse cells including oligodendrocyte progenitor cells, multipotent stem cells, and macrophage/monocyte lineage (Hill and Nishiyama, 2014;Matsumoto et al, 2008). In addition, the presence of CaSR-positive cells in perivascular regions appeared to correlate temporally and spatially with the presence of neural stem/progenitor cells potentially originating from perivascular cells/microvascular pericytes (Nakagomi et al, 2011;Nakagomi et al, 2009;Nakano-Doi et al, 2010).…”

Regulation of astroglia by gonadal steroid hormones under physiological and pathological conditions

“…These cells are widely distributed throughout the brain parenchyma and are characterized by the expression of the NG2 antigen and the alpha receptor for plateletderived growth factor (Pdgfra) (Nishiyama, 2007;Nishiyama et al, 1996). NG2 cells are precursors for myelinating oligodendrocytes (Polito and Reynolds, 2005;Raff et al;Watanabe et al, 2002;Zhu et al, 2008), but they are also involved in maintaining brain homeostasis through different mechanisms that are still being investigated (Birey et al, 2015;Dimou and Gallo, 2015;Hill and Nishiyama, 2014;Nishiyama et al, 2015).…”

Oligodendrocyte Precursor Cells Modulate the Neuronal Network by Activity-Dependent Ectodomain Cleavage of Glial NG2

“…Studies to date have only described a unidirectional communication between neurons and OPC at synapses [8],[26]. The NG2 protein contains two neurexin-like (lamininG-neurexin-sex hormone binding globulin [LNS]) domains at the N-terminus [27], suggesting it may function at synapses similar to LNS domain containing neurexins [28],[29].…”