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The Mechanics of (Poro-)Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton
Published on: March 10, 2023
Elasticity in ionically cross-linked neurofilament networks
Norman Y Yao1, Chase P Broedersz, Yi-Chia Lin
1Department of Physics, Harvard University, Cambridge, Massachusetts, USA. nyao@fas.harvard.edu
Biophysical Journal
|May 21, 2010
Summary
Neurofilaments form a protective neuronal cytoskeleton. Divalent ions like Mg(2+) cross-link neurofilaments, creating solidlike elastic networks that stiffen under strain, crucial for neuron mechanical stability.
Area of Science:
- Biophysics
- Neuroscience
- Materials Science
Background:
- Neurofilaments are key components of the neuronal cytoskeleton, providing structural support.
- Understanding their mechanical properties is vital for comprehending neuronal protection against stress.
Purpose of the Study:
- To investigate the viscoelastic properties of neurofilament networks.
- To determine the role of divalent ions in neurofilament network mechanics.
Main Methods:
- Measurement of linear and nonlinear viscoelastic properties of neurofilament networks.
- Analysis of neurofilament behavior in the presence of divalent cations (Mg(2+), Ca(2+), Zn(2+)).
- Application of a cross-linked semiflexible network model.
Main Results:
- Neurofilament networks exhibit soft solid behavior with significant strain stiffening at critical strains (30-70%).
- Divalent ions function as effective cross-linkers, modulating the elastic response of these networks.
- The elasticity is entropic and consistent with a model for cross-linked semiflexible polymers.
Conclusions:
- Divalent ions play a crucial role in the mechanical integrity of neurofilaments, similar to actin-binding proteins.
- The findings provide a quantitative understanding of neurofilament network mechanics and cross-linking.
- This research offers insights into the biophysical basis of neuronal structural stability.
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