在脑病理状态下星形胶质细胞介导的突触重塑

Astrocyte-mediated synapse remodeling in the pathological brain

星形胶质细胞是胶质细胞的主要类型,对神经元突触间的信号传递和联系起到反馈作用,构成"三重突触结构"。在大脑发育的过程中,星形胶质细胞的代谢型谷氨酸受体介导钙离子波并释放胶质递质或突触发生分子,介导神经元.胶质细胞间的联系,但在成年大脑中,尚不清楚是否存在此信号通路。但越来越多的证据显示,当成年大脑处于病理状态下,成熟的星形胶质细胞也重新表现出非成熟星形胶质细胞的表型。星形胶质细胞表型的这种非成熟转变可以导致神经环路和突触的重塑。在本综述中,笔者总结了大脑发育过程中星形胶质细胞介导的突触重塑,讨论了成年脑病理过程中非成熟星形胶质细胞信号通路的重现,并重点讨论这些信号通路对病理过程中与脑功能改变有关的突触连接重塑的意义。

Astrocytes, a major type of glia, reciprocally influence synaptic transmission and connectivity, form- ing the ＂tripartite synapses＂. Astrocytic metabotropic glutamate receptor （mGluR）-mediated Ca 2＋ waves and re- lease of gliotransmitters or synaptogenic molecules mediate this neuron-glia interaction in the developing brain, but this signaling has been challenged for adult brain. However, cumulative evidence has suggested that mature astrocytes exhibit re-awakening of such immature phenotype in the pathological adult brain. This phenotypic change in astrocytes in response to injury may induce neural circuit and synapse plasticity. In this review article, we summarize astrocyte-mediated synapse remodeling during physiological development, discuss re-emergence of immature astrocytic signaling in adult pathological brain, and finally highlight its contribution to significant modification of synaptic connections correlating with functional progress of brain pathology.