Homeostatic Microglia Antibody Marker Kit

Microglia are the resident immune cells of the central nervous system (CNS), which represent 5-12% of total cells in the healthy brain and the spinal cord. Microglia are long-lived, self-renewing cells, autonomous from peripheral monocytes¹. They are derived from the myeloid precursor cells in the embryonic yolk sac and travel to the area of the developing CNS during early embryogenesis. They are broadly distributed throughout the CNS although quantity and location vary among species. Despite their broad distribution, microglia are rather heterogeneous with different subpopulations based on specific brain regions².

Under normal/physiological conditions, microglia are maintained in a steady, or ramified, state characterized by a stable, nonmotile cell body and an extensive network of thin processes that continually elongate and retract. These movements are used to scan the surrounding area for disturbances in homeostasis that need to be resolved. Upon detection of environmental changes such as an immune threat, microglia undergo morphological changes to take on an amoeboid shape and become phagocytic to remove the encountered threat. These morphological changes are also accompanied by expression and secretion of inflammatory molecules such as cytokines and chemokines, which help microglia communicate with astrocytes and peripheral immune cells³.

In addition to this well characterized role as the CNS macrophages, recent findings point to major functions for microglia in instructing and regulating the proper function of the neuronal networks in the adult CNS, by orchestrating construction of the whole network during development⁴.

Steady-state/homeostatic microglia express several markers, some of which are shared with macrophages. These markers can be used to differentiate homeostatic microglia from activated microglia.