NG2-神经元突触联系在NG2细胞增殖分化过程中的变化

NG2细胞是广泛分布于CNS中表达NG2蛋白多糖的一种胶质细胞，也被称为少突胶质前体细胞（oligodendrocyteprecur—sorcells，oPc）。该细胞具有典型复杂的星形形态和长突起围绕于胞体周围，表达电压门控的K＋和Na＋通道、GABAA以及AMPA／红藻氨酸受体并接受神经元突触的信号输入。NG2细胞增殖分化是保证神经元轴突髓鞘化的首要前提，NG2的增殖分化不能仅依靠其自身调控，NG2-神经元突触联系可能也是调控NG2细胞增殖分化的信息中转站。伴随NG2细胞增殖分化神经元轴突的髓鞘化也不断形成，这些过程在围生期表现尤为明显；NG2细胞分化为少突胶质细胞后，其功能上具有”专一性”，所以可能存在NG2．神经元突触联系的作用被削弱的现象。因此，在NG2细胞增殖过程中，NG2细胞保持与神经元之间的功能性突触并将其传递给子代NG2细胞；而在NG2细胞分化的过程中，NG2细胞的突触信号输入迅速减少。NG2细胞不但是一种前体细胞，同时也是一种具有独特功能的胶质细胞，在中枢神经系统中发挥重要作用。本综述就NG2细胞在增殖分化过程中其突触信号的变化以及可能的意义进行阐述。

Changes of NG2-neuron Synapses during Proliferation and Differentiation of NG2 Cells

NG2 cell is one type of glia expressing proteoglycan NG2, also known as oligodendrocyte precursor cells, which are widespread in the grey and white matter of the CNS. NG2 cells have a complex stellate morphology, with highly branched processes around the cell body. NG2 cells express a complex set of voltage-gated K~ and Na＋ channels, GABAA receptors and AMPA/kainate re- ceptors, and receive synaptic signals input from neurons. Proliferation and differentiation of NG2 cells is to ensure that the most impor- tant prerequisite for axon myelination, while it not only rely on its own regulation, Synaptic connections of NG2 cells and neurons is a in- formation transfer station to regulate Proliferation and differentiation of NG2 cells, accompanied NG2 cell proliferation and differentia- tion process of axon myelination constantly forming, particularly obvious manifestations of these processes in the perinatal period; NG2 cell differentiation as having a specific function of oligodendrocyte.So the effect of Synaptic connections of NG2 cells and neurons would be weakened. Therefore,NG2 cells keep functional synapses during mitosis and pass them onto their progeny, while synaptic signaling are rapidly decreased during differentiation of NG2 cells. NG2 cells, on one hand, are not only immature progenitor cells, while on the other hand they also show specific features of differentiated cells that play unique physiological roles in the central nervous system. This review highlights new find related to the changes of NG2-neuron synapse during NG2 cell proliferation and differentiation and the possi- ble significance of it.