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Edited By: Eduardo Macagno, Darcy B. Kelley, Moses V. Chao, Mu-Ming Poo, and Paola Bovolenta
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ISI Journal Citation Reports © Ranking: 2015: 17/41 (Developmental Biology); 146/256 (Neurosciences)
Online ISSN: 1932-846X
Growth Cone Dynamics and Aspects of Neurite Outgrowth
This inaugural On-Line Virtual Issue is being made available to our on-line readers in conjunction with the publication of an issue of Developmental Neurobiology that includes a tribute from students and colleagues to Paul Letourneau, in celebration of his many contributions on the occasion of a significant milestone, his 64th birthday.
This On-Line Virtual Issue is comprised of significant articles recently published in Developmental Neurobiology in the area of growth cone dynamics and process outgrowth, ranging from Semaphorin -induced growth cone collapse to growth cone-like waves and their role in axonogenesis, from the role of tension in axon growth to substrate-dependence of the action of myosin II, and from the role of ADF/cofilin in axon turning to the use of Drosophila growth cones in genetic analyses of regulatory networks responsible for axon growth.
Brown, J.A., and Bridgman, P.C. 2009. Disruption of the cytoskeleton during Semaphorin 3A induced growth cone collapse correlates with differences in actin organization and associated binding proteins. Dev Neurobiol. 69:633-46.
Actin depolymerization followed by partial depolymerization of fascin-associated actin bundles and their movement to the neurite, where they may function as the substrate for actomyosin contractions, result in growth cone collapse.
Waves are dynamic structures that travel in processes of both cultured and brain slice neurons and contribute to axon growth and branching via the transport of actin and enhancement of growth cone size and motility.
Wnt/Ryk calcium signaling mechanisms that regulate axon outgrowth and repulsion in cortical cultures are also essential for growth and guidance of post-crossing callosal axons involving axon repulsion through CaMKII.
The role of myosin II in axon extension is to mediate substratum attachment on laminin, but to inhibit microtubule advance into growth cones in neurons growing on polylysine.
Tension applied to the cell body or to the growth cone suggests that axon elongation is enhanced by viscoelastic stretching and volume addition along the axon.
Adhesion molecules guide neuronal growth cones and underlying microtubule rearrangements by differentially regulating microtubule–actin coupling and actin movements and not by controlling plus-end polymerization rates.
Arachidonic acid, generated postsynaptically by cPLA2 downstream of Ca2+ entry through NMDARs, acts as a retrograde signal to regulate the dynamic growth of retinal arbors.
Marsick, B.M., Flynn, K.C., Santiago-Medina, M. Bamburg, J.R. and Letourneau, P.C. 2010. Activation of ADF/cofilin mediates attractive growth cone turning toward nerve growth factor and netrin-1. Dev Neurobiol 70:565-588.
Gradients of NGF and netrin-1 locally activate ADF/Cofilin to promote actin polymerization and subsequent growth cone turning toward the side containing higher ADF/Cofilin activity.
Sánchez-Soriano, N., Gonçalves-Pimentel, C., Beaven, R., Haessler, U., Ofner-Ziegenfuss, L., Ballestrem C. and Prokop, A. 2010. Drosophila growth cones: A genetically tractable platform for the analysis of axonal growth dynamics. Dev Neurobiol. 70:58-71.
Drosophila GCs are shown to be a useful model for the application of combinatorial genetics to address the complexity of regulatory networks governing axonal growth.
Ephrin-A5 inhibits Erk activity but activates c-Jun N-terminal kinase, but regulation of these two pathways is not required for ephrin-A5-induced growth cone collapse in hippocampal neurons.