The Neuronal Actin Cytoskeleton and the Protrusion of Lamellipodia and Filopodia

The protrusion of filopodia and lamellipodia from the surface of neurons is fundamental to axon extension, guidance, the formation of axon branches, and synaptic structures Protrusion is driven by the polymerization and controlled organization of actin filament arrays This chapter provides an overview of the basic mechanisms operative during protrusion Mechanisms underlying the suppression of protrusive activity are also discussed in relation to the regulation of axonal morphology The purpose of this chapter is to provide the reader with an understanding of the major concepts underlying the regulation of actin filaments in protrusion without delving deeply into the molecular mechanisms, which are discussed in other chapters of this volume Focus is placed on the organization of actin filaments in protrusive structures and how the organization relates to the process of protrusion