The role of microglia in the healthy brain

Abstract

Microglia were recently shown to play unexpected roles in normal brain development and adult physiology. This has begun to dramatically change our view of these resident "immune" cells. Here, we briefly review topics covered in our 2011 Society for Neuroscience minisymposium "The Role of Microglia in the Healthy Brain." This summary is not meant to be a comprehensive review of microglia physiology, but rather to share new results and stimulate further research into the cellular and molecular mechanisms by which microglia influence postnatal development, adult neuronal plasticity, and circuit function.

Figure 1.

Overview of microglial behavior in the healthy brain. Highly motile microglial processes continuously remodel their local environment (left), structurally and functionally interact with synaptic elements (middle; dendritic branch and spines, green) through direct contacts and exchanges of molecular signals, and contribute to restructuring of neuronal circuits by phagocytosing synaptic elements and newborn cells (right; cellular inclusions, blue and green). Microglial morphology and behavior display variability across CNS regions and stages of the lifespan.