Microglial Cells Function in the Central Nervous System

Abstract

Microglia are the resident macrophages of the central nervous system (CNS). These cells of mesodermal/mesenchymal origin migrate into all regions of the CNS. Recent studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains. By a large number of signaling pathways, they can communicate with macroglial cells (e.g. astrocytes) and neurons and with cells of the immune system. Under normal physiological conditions, microglia constantly monitor their microenvironment and survey neurons. Microglia have other functions including the participation in the formation of new blood vessels or angiogenesis, cognitive function, the regulation of synaptic plasticity, and neurogenesis and they play a crucial role in the CNS through communication with other brain cells. This chapter will provide an overview of the functions of microglial cells within the CNS.