Microglial phenotype: is the commitment reversible?

Trends Neurosci. 2006 Feb;29(2):68-74. doi: 10.1016/j.tins.2005.12.005. Epub 2006 Jan 6.


Microglia, the standby cells for immune defense in the CNS, have a reputation for exacerbating the neural damage that occurs in neurodegenerative diseases. However, research over the past few years has established that microglia do not constitute a single, uniform cell population, but rather comprise a family of cells with diverse phenotypes--some that are beneficial and others that the CNS can barely tolerate and that are therefore destructive. This finding raised several questions. What instructs microglia to acquire a particular phenotype, and how do these phenotypes differ? How committed are microglia to a specific phenotype? Can destructive microglia become protective, and can protective microglia retain their beneficial phenotype even when they encounter a destructive environment? Here, we address these questions, and the background of research that elicited them.

Publication types

  • Review

MeSH terms

  • Animals
  • Humans
  • Inflammation / pathology
  • Microglia / physiology*
  • Phenotype