Figure 5: Fate of neuron-NG2 cell synapses during NG2 cell proliferation and differentiation. NG2 cells keep functional synapses during division; NG2 daughter cells could also form synapses with neurons or undergo differentiation. When NG2 cells differentiate into premyelinating oligodendrocytes, the synaptic contacts between neurons and NG2 cells were rapidly decreased, accompanied with the disruption of synaptic structures and the decrease of glutamate receptors on NG2 cells. As premyelinating oligodendrocytes grow into mature oligodendrocytes, the processes of oligodendrocytes contact neuronal axons and form myelin sheaths. This process may be regulated by other modes of signal transmission as well.