Astrocytes are glial cells (sees Glossary) of neural progenitor origin that contiguously tile the entire mammalian central nervous system (CNS) where they constitute one of the most abundant cell populations and provide multiple activities essential for CNS functions in health and disease [1]. Astrocytes interact with both neural and non-neural cells, including neurons and their synapses, oligodendrocytes, oligodendrocyte progenitor cells (OPC), microglia, various peri-vascular cells, meningeal fibroblasts and circulating immune cells. In heathy CNS tissue, astrocytes maintain homeostasis of extracellular fluids, ions and transmitters [2], provide glucose metabolites as energy substrates to neurons [3], modulate local blood flow [4], help regulate drainage of interstitial fluid [5], play essential roles in synapse development and plasticity [6], and exhibit dynamic activities crucial for neural circuit function, neurological function and behavior [7].
