Signaling events regulating microglial functions and activation phenotypes

小胶质细胞是大脑的免疫细胞，它们保护大脑免受病原体的侵害。此外，小胶质细胞吞噬活性、细胞因子产生和营养因子分泌调节神经元可塑性，这是允许大脑重组其神经连接以响应新情况的关键现象。虽然调节的小胶质细胞活性是有益的，但失调的小胶质细胞作用可引起神经元功能障碍并促进认知缺陷和神经元死亡。小胶质细胞的这些相反的作用是可行的，因为它们的不同功能归因于特定的激活表型。

Microglia are the immune cells of brain, which they protect from pathogens. In addition, microglial phagocytosis activity, cytokine production, and trophic factor secretion regulate neuronal plasticity, the key phenomenon that allows brain to reorganize its neural connections in response to new situations. While modulated microglial activity is beneficial, dysregulated microglial actions can cause neuronal dysfunction and promote cognitive deficits and neuronal death. These opposite roles of microglia are feasible because of their diverse functions attributed to specific activation phenotypes.