Neuron–glia synapses in the brain: properties, diversity and functions of NG2 glia
Tóm tắt
Although NG2 glial cells represent a frequent glial cell type in the brain, characterized by expression of the NG2 proteoglycan, the functional impact of these cells is still enigmatic. A large proportion of NG2 glia are proliferatively active throughout life. These cells express a plethora of ion channels and transmitter receptors, which enable them to detect neuronal activity. Intriguingly, NG2 glial cells receive synaptic input from glutamatergic and GABAergic neurons. Since these postsynaptic glial currents are very small, their spatial and temporal integration might play an important role. In white matter, most NG2 glial cells differentiate into oligodendrocytes and this process might be influenced through the activity of the aforementioned neuron–glia synapses. Increasing evidence suggests that the properties of NG2 glia vary across brain regions; however, the impact of this variability is not understood yet.
Tài liệu tham khảo
Bergles DE, Jabs R, Steinhäuser C (2010) Neuron-glia synapses in the brain. Brain Res Rev 63:130–137
Chittajallu R, Chen Y, Wang H, Yuan X, Ghiani CA, Heckman T, McBain CJ, Gallo V (2002) Regulation of Kv1 subunit expression in oligodendrocyte progenitor cells and their role in G1/S phase progression of the cell cycle. Proc Natl Acad Sci U S A 99:2350–2355
Haberlandt C, Derouiche A, Wyczynski A, Haseleu J, Pohle J, Karram K, Trotter J, Seifert G, Frotscher M, Steinhäuser C, Jabs R (2011) Gray matter NG2 cells display multiple Ca-signaling pathways and highly motile processes. PLoS One 6:e17575
Hughes EG, Kang SH, Fukaya M, Bergles DE (2013) Oligodendrocyte progenitors balance growth with self-repulsion to achieve homeostasis in the adult brain. Nat Neurosci 16:668–676
Chittajallu R, Aguirre A, Gallo V (2004) NG2-positive cells in the mouse white and grey matter display distinct physiological properties. J Physiol 561:109–122
Passlick S, Grauer M, Schäfer C, Jabs R, Seifert G, Steinhäuser C (2013) Expression of the gamma2-subunit distinguishes synaptic and extrasynaptic GABA(A) receptors in NG2 cells of the hippocampus. J Neurosci 33:12030–12040
Balia M, Velez-Fort M, Passlick S, Schafer C, Audinat E, Steinhäuser C, Seifert G, Angulo MC (2015) Postnatal down-regulation of the GABAA receptor gamma2 subunit in neocortical NG2 cells accompanies synaptic-to-extrasynaptic switch in the GABAergic transmission mode. Cereb Cortex 25:1114–1123
Bergles DE, Roberts JD, Somogyi P, Jahr CE (2000) Glutamatergic synapses on oligodendrocyte precursor cells in the hippocampus. Nature 405:187–191
Sun W, Dietrich D (2013) Synaptic integration by NG2 cells. Front Cell Neurosci 7:255