Cytoskeletal Dynamics Underlying Neurite Outgrowth

• Published in: Developmental cell 2008-07, Vol.15 (1), p.146-162
• Main Authors: Schaefer, Andrew W, Schoonderwoert, Vincent Th.G., Ji, Lin, Mederios, Nelson, Danuser, Gaudenz, Forscher, Paul
• Format: Article
• Language: English
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/j.devcel.2008.05.003

Although much evidence suggests that axon growth and guidance depend on well-coordinated cytoskeletal dynamics, direct characterization of the corresponding molecular events has remained a challenge. Here, we address this outstanding problem by examining neurite outgrowth stimulated by local application of cell adhesion substrates. During acute outgrowth, the advance of organelles and underlying microtubules into the central domain was correlated with regions of attenuated retrograde actin network flow in the periphery. Interestingly, as adhesion sites matured, contractile actin arc structures, known to be regulated by the Rho/Rho Kinase/myosin II signaling cascade, became more robust and coordinated microtubule movements in the growth cone neck. When Rho Kinase was inhibited, although growth responses occurred with less of a delay, microtubules failed to consolidate into a single axis of growth. These results reveal a new role for Rho Kinase and myosin II contractility in regulation of microtubule behavior during neuronal growth.