title: Microglia: new roles for the synaptic stripper.
abstract: Any pathologic event in the brain leads to the activation of microglia, the immunocompetent cells of the central nervous system. In recent decades diverse molecular pathways have been identified by which microglial activation is controlled and by which the activated microglia affects neurons. In the normal brain microglia were considered "resting," but it has recently become evident that they constantly scan the brain environment and contact synapses. Activated microglia can remove damaged cells as well as dysfunctional synapses, a process termed "synaptic stripping." Here we summarize evidence that molecular pathways characterized in pathology are also utilized by microglia in the normal and developing brain to influence synaptic development and connectivity, and therefore should become targets of future research. Microglial dysfunction results in behavioral deficits, indicating that microglia are essential for proper brain function. This defines a new role for microglia beyond being a mere pathologic sensor.
authors: Max-Delbrück Center for Molecular Medicine, 13125 Berlin, Germany. kettenmann@mdc-berlin.de
authors: Helmut
authors: H
authors: Kettenmann
authors: Frank
authors: F
authors: Kirchhoff
authors: Alexei
authors: A
authors: Verkhratsky
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000473:pathology; D002450:Cell Communication / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D006801:Humans; D017628:Microglia / Q000473:pathology / Q000502:physiology*; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000473:pathology / Q000502:physiology; D013569:Synapses / Q000473:pathology / Q000502:physiology*