Abstract Glia, Greek for “glue,” was discovered by Rudolph Virchow, a German anatomist, in the mid-nineteenth century. The name reflects the original view that glia played merely a structural or metabolic support role for neurons. Glial cells, especially astrocytes, are much more than glue or merely quiescent and display their own set of activities. Studies over the last 20 years show that astrocytes perform a series of complex functions that go well beyond the uptake and recycling of neurotransmitters and the buffering of extracellular potassium.1,2