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The role of microglia at synapses in the healthy CNS: novel insights from recent imaging studies

Published online by Cambridge University Press:  15 March 2012

Marie-Ève Tremblay*
Affiliation:
Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
*
Correspondence should be addressed to: Marie-Ève Tremblay, Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719, USA phone: 585-474-8300 email: tremblay2@wisc.edu

Abstract

In the healthy brain, quiescent microglia continuously remodel their shape by extending and retracting highly motile processes. Despite a seemingly random sampling of their environment, microglial processes specifically interact with subsets of synaptic structures, as shown by recent imaging studies leading to proposed reciprocal interactions between microglia and synapses under non-pathological conditions. These studies revealed that various modalities of microglial dynamic behavior including their interactions with synaptic elements are regulated by manipulations of neurotransmission, neuronal activity and sensory experience. Conversely, these observations implied an unexpected role for quiescent microglia in the elimination of synaptic structures by specialized mechanisms that include the phagocytosis of axon terminals and dendritic spines. In light of these recent discoveries, microglia are now emerging as important effectors of neuronal circuit reorganization.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2012

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