Microglia, the tissue-resident macrophages of the central nervous system (CNS) parenchyma, are vital for maintaining tissue integrity and homeostasis1. They are not only involved in the clearance of cellular debris or pathogens but also shape synaptic plasticity and promote myelination of axons during development2–4. Their homeostatic phenotype and functions depend on instructive signals from the environment, such as TGF-β or CSF1R-ligands5–7, and accordingly, elaborated single-cell transcriptomic analyses revealed that such environmental cues cause a pronounced regional heterogeneity in microglia throughout the CNS8,9.
