Homeostasis of Microglia in the Adult Brain: Review of Novel Microglia Depletion Systems

Trends Immunol. 2015 Oct;36(10):625-636. doi: 10.1016/j.it.2015.08.005.


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.

Keywords: depletion systems; development; erythromyeloid precursors; macrophages; maintenance; microglia; repopulation; yolk sac.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Brain / physiology*
  • Cell Differentiation
  • Disease Models, Animal
  • Embryonic Development
  • Homeostasis*
  • Humans
  • Inflammation
  • Macrophages / cytology
  • Macrophages / immunology
  • Macrophages / metabolism
  • Microglia / cytology
  • Microglia / physiology*
  • Models, Animal
  • Neuroimmunomodulation