The axonal actin-spectrin lattice acts as a tension buffering shock absorber.
| Autor: | Dubey S; Raman Research Institute, Bangalore, India., Bhembre N; Raman Research Institute, Bangalore, India., Bodas S; Indian Institute of Science Education and Research, Pune, India., Veer S; Raman Research Institute, Bangalore, India., Ghose A; Indian Institute of Science Education and Research, Pune, India., Callan-Jones A; Laboratory of Complex Materials Systems, Paris Diderot University, Paris, France., Pullarkat P; Raman Research Institute, Bangalore, India. |
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| Jazyk: | angličtina |
| Zdroj: | ELife [Elife] 2020 Apr 08; Vol. 9. Date of Electronic Publication: 2020 Apr 08. |
| DOI: | 10.7554/eLife.51772 |
| Abstrakt: | Axons span extreme distances and are subject to significant stretch deformations during limb movements or sudden head movements, especially during impacts. Yet, axon biomechanics, and its relation to the ultrastructure that allows axons to withstand mechanical stress, is poorly understood. Using a custom developed force apparatus, we demonstrate that chick dorsal root ganglion axons exhibit a tension buffering or strain-softening response, where its steady state elastic modulus decreases with increasing strain. We then explore the contributions from the various cytoskeletal components of the axon to show that the recently discovered membrane-associated actin-spectrin scaffold plays a prominent mechanical role. Finally, using a theoretical model, we argue that the actin-spectrin skeleton acts as an axonal tension buffer by reversibly unfolding repeat domains of the spectrin tetramers to release excess mechanical stress. Our results revise the current viewpoint that microtubules and their associated proteins are the only significant load-bearing elements in axons. Competing Interests: SD, NB, SB, SV, AG, AC, PP No competing interests declared (© 2020, Dubey et al.) |
| Databáze: | MEDLINE |
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