Recent topics regarding macrophage in the central nervous system

The central nervous system (CNS) is a highly complex collection of neurons with a variety of stromal cells, such as glia cells, immune cells, vascular cells and fibroblasts. Microglia are a resident macrophage and a type of glial cells located in the parenchyma of the CNS and play a pivotal role in the maintenance of tissue homeostasis. They are early responders to the abnormality of the CNS, leading to the adaptation of their phenotypes by virtue of their plasticity, after which they give an impact on neuronal functions. Besides microglia, there are anatomically and phenotypically distinct macrophage populations at the border of the CNS, such as meninge, perivascular space and choroid plexus, where they show distinct morphology and gene expression profiles when compared with microglia. This review will summarize the recent advance in our knowledge regarding their heterogeneity, plasticity, ontogenetic relationship of these CNS-resident macrophage populations.

Automated summary

The central nervous system (CNS) consists of neurons and various stromal cells, with microglia being a type of glial cells that play an important role in maintaining tissue homeostasis. They respond early to CNS abnormalities and can impact neuronal functions through their plasticity. There are also distinct macrophage populations at the border of the CNS, such as meninges and choroid plexus, which have different morphology and gene expression profiles compared to microglia. This review summarizes recent advances in understanding the heterogeneity, plasticity, and ontogenetic relationship of these CNS-resident macrophage populations.