ABSTRACT
Glial cells have been described as having a supporting role to neurons in normal brain function and pathology. However, during the last two decades important new information has emerged on new roles for glial cells in brain development, as neuronal precursors, in the regulation of synaptic function, and in brain injury and repair (Goldman, 2003; Horner and Plamer, 2003; Newman, 2003; Ransom et al., 2003; Slezak and Pfrieger, 2003). Some of these functions are discussed in other chapters of this book. These new biological functions ascribed to glial cells bring them to the forefront of neuroscience research. I should note that although oligodendrocytes are an important glial cell type, in this chapter I will refer to glial cells primarily as microglia and astrocytes.
