Neuronal integrity and complement control synaptic material clearance by microglia after CNS injury.

Journal Article (Journal Article)

Phagocytosis of synaptic material by microglia is critical for central nervous system development. Less well understood is this microglial function in the injured adult brain. Assay of microglial phagocytosis is challenging, because peripheral myeloid cells engraft the site of injury, which could obscure interpretation of microglial roles. The model used here, optic nerve crush injury, results in degeneration of synapses in the dorsal lateral geniculate nucleus (dLGN), which stimulates rapid activation and engulfment of synaptic material by resident microglia without myeloid cell engraftment. Pharmacological depletion of microglia causes postinjury accumulation of synaptic debris, suggesting that microglia are the dominant postinjury phagocytes. Genetic or pharmacological manipulations revealed that neuronal activity does not trigger microglia phagocytosis after injury. RNA sequencing reveals C1q and CD11b/CR3 involvement in clearance of debris by dLGN-resident microglia. Indeed, C1qa-/- and Itgam-/- mice exhibit impaired postinjury debris clearance. Our results show how neurodegenerative debris is cleared by microglia and offers a model for studying its mechanisms and physiological roles.

Full Text

Duke Authors

Cited Authors

  • Norris, GT; Smirnov, I; Filiano, AJ; Shadowen, HM; Cody, KR; Thompson, JA; Harris, TH; Gaultier, A; Overall, CC; Kipnis, J

Published Date

  • July 2, 2018

Published In

Volume / Issue

  • 215 / 7

Start / End Page

  • 1789 - 1801

PubMed ID

  • 29941548

Pubmed Central ID

  • PMC6028515

Electronic International Standard Serial Number (EISSN)

  • 1540-9538

Digital Object Identifier (DOI)

  • 10.1084/jem.20172244


  • eng

Conference Location

  • United States