• © 2010 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. Spanning a period of a few decades, there have been several models proposed for the elasticity or viscoelasticity of the cytoskeleton. In addition, there have been numerous experiments using cells and reconstituted actin gels, with or without cross-linkers, designed to characterize the rheology of actin networks under various conditions. Still, debates continue regarding the contributions of various potential mechanisms (filament bending stiffness, thermal fluctuations, filament extensional stiffness, cross-linker stiffness, cross-link binding and unbinding) to cell viscoelasticity, and which model (semiflexible polymer network, tensegrity network, cellular solids) is best able to capture the measured characteristics. Here, we use a computational model of a thermally-active cross-linked network to probe the important factors and discuss these in the context of the different models. We conclude that thermal fluctuations are not important in the cytoskeleton, in contrast to the semiflexible polymer network theory. However, both the cellular solids and tensegrity models fail to capture some of the salient mechanical features. For cross-linked networks under prestress, the tensegrity model appears to be the most consistent with the results of our simulations. However, currently no single model satisfactorily captures viscoelastic behaviors of actin networks over a wide range of conditions. Our simulation scheme provides a basis for delineating multiple mechanisms involved in this complex system.

author list (cited authors)

  • KAMM, R. D., KIM, T., & HWANG, W.

citation count

  • 0

Book Title

  • Tributes to Yuan-Cheng Fung on His 90th Birthday

publication date

  • December 2009