title: Homeostasis of Microglia in the Adult Brain: Review of Novel Microglia Depletion Systems.
abstract: Microglia are brain macrophages that emerge from early erythro-myeloid precursors in the embryonic yolk sac and migrate to the brain mesenchyme before the blood brain barrier is formed. They seed the brain, and proliferate until they have formed a grid-like distribution in the central nervous system that is maintained throughout lifespan. The mechanisms through which these embryonic-derived cells contribute to microglia homoeostasis at steady state and upon inflammation are still not entirely clear. Here we review recent studies that provided insight into the contribution of embryonically-derived microglia and of adult 'microglia-like' cells derived from monocytes during inflammation. We examine different microglia depletion models, and discuss the origin of their rapid repopulation after depletion and outline important areas of future research.
authors.affiliation: Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany. Electronic address: waisman@uni-mainz.de.
authors.forename: Ari
authors.initials: A
authors.lastname: Waisman
authors.affiliation: Singapore Immunology Network (SIgN), Agency for Science, Technology, and Research (A*STAR), 138648 Singapore, Singapore.
authors.forename: Florent
authors.initials: F
authors.lastname: Ginhoux
authors.affiliation: Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland.
authors.forename: Melanie
authors.initials: M
authors.lastname: Greter
authors.affiliation: Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Bruttger
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D002454:Cell Differentiation; D004195:Disease Models, Animal; D047108:Embryonic Development; D006706:Homeostasis; D006801:Humans; D007249:Inflammation; D008264:Macrophages / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D017628:Microglia / Q000166:cytology / Q000502:physiology*; D023421:Models, Animal; D015213:Neuroimmunomodulation
keywords: depletion systems; development; erythromyeloid precursors; macrophages; maintenance; microglia; repopulation; yolk sac