小胶质细胞在脑中的生理功能

小胶质细胞是脑中的巨噬细胞,也是脑实质中唯一的一种免疫细胞,因而被看作是中枢神经系统抵御病原入侵的第一道防线。在其他非感染病理状态下,如脑损伤及神经退行性疾病等,小胶质细胞也发挥着保护和毒性损伤的双重作用。相比较其病理功能,人们对小胶质细胞的生理功能长期以来很少关注。然而,近几年关于小胶质细胞生理功能的研究在多个方面都有突破。这些研究结果揭示,小胶质细胞在发育的神经系统中起着调控神经元存活和修饰突触的作用,并且在成熟的健康脑中具有探测和调控神经元活动的功能。将着重对近几年关于小胶质细胞生理功能的相关研究做一综述。

The multiple roles played by microglia

Microglia are the macrophages in the brain and are the only subset of immune cells in the brain parenchyma. Previous studies about microglia have been mainly focusing on their protection of the brain from pathogen invasions and their protective or toxic roles in the degenerative diseases. In contrast to the abundant knowledge of their pathological roles, little is known about the physiological functions of microglia. Interestingly, recent studies have revealed that microglia play key roles in both the developmental and the mature healthy brains. During the neural development, microglia regulate neurogenesis as well as neuronal death and play key roles in synapse pruning. In the mature healthy brains, microglia detect and regulate neuronal activities. In this review, we will focus on the most recent discoveries ofmicroglial functions in the healthy brain.