EGF is a critical growth factor regulating neural progenitor cell proliferation in the SVZ [Figure 1; (Kuhn et al., 1997)]. The cellular response to EGF is initiated by rapid kinetics of receptor activation, followed by phosphorylation-dependent activation of signaling cascades. This is typically analyzed by observing activation of the ERK MAPKs and subsequent transcriptional activation of immediate-early genes [(IEGs), (Amit et al., 2007)]. EGFR is a receptor tyrosine kinase of the ErbB family, critical signaling molecules of cell proliferation and fate determination (Bublil and Yarden, 2007). The epidermal growth factor (EGF) ErbB system is one of the best studied signaling networks. Among all members of the large family of growth factor receptor tyrosine kinases (RTKs), the ErbB family (also called the type I RTKs) is considered the prototypic founder sub-group of the RTK super-family, which includes 18 other small sub-groups of related receptors. Erbb4 is autonomous; when bound by a ligand growth factor it undergoes dimerization and generates intracellular signals culminating in cell proliferation, migration or differentiation (Bublil and Yarden, 2007).
