Origin, Diversity, and Roles of Microglia

Microglia serve as the innate immune cells within the central nervous system (CNS). Their structure mirrors their role, transitioning from a complex, branching form in the healthy brain to a more dynamic, amoeboid shape when responding to pathological conditions. Acting as the brain’s resident macrophages, microglial cells swiftly react to injuries or invading pathogens. Recent research has shed light on their pivotal role in normal brain function, particularly through the release of various cytokines that significantly influence synaptic plasticity and cognitive processes. In this chapter, the origin and the different activation states of microglia are discussed. Additionally, their functions during CNS development, immune surveillance, and their impact on neuronal networks and synaptic plasticity under both normal and pathological circumstances are examined. Notably, targeting microglia could hold promise as a therapeutic approach for neuroimmune disorders.