Figure 9.

Model of PAK1 regulating actin dynamics throughout the oligodendrocyte lineage. A, PAK1 regulates actin dynamics in OPC processes and during myelination. PAK1 may promote myelination by regulating actin dynamics at the leading edge during myelination. B–E, Model showing actin dynamics during oligodendrocyte process extension, axon ensheathment, and myelination in lateral and cross-sectional views. D, E, Different representations during myelination: (D) focus on the hypothesized force driving myelin wrapping; and (E) focus on the lateral extension. D, F-actin (lines) and G-actin (dots) are pictured in the inner tongue for visualization. F-actin pushes the inner tongue between previous myelin wraps and the axon. E, G-actin is pictured in the middle myelin wrap for visualization but is present in all layers.