A viscoelastic model for axonal microtubule rupture.

Area of Science:

• Neuroscience
• Biophysics
• Materials Science

Background:

• Axonal microtubules, crucial for neuronal structure, are bundled by microtubule-associated protein tau.
• Tau protein cross-linking reinforces microtubules, enhancing their compressive load-bearing capacity.
• Under traumatic brain injury, microtubules experience tensile forces, potentially leading to rupture.

Purpose of the Study:

• To computationally simulate the dynamic response of axonal microtubules under tensile forces.
• To investigate the influence of force rate and magnitude on microtubule bundle deformation.
• To predict critical regions within microtubule bundles susceptible to failure.

Main Methods:

• Development of a computational model using discrete masses and the Standard Linear Solid (SLS) viscoelastic model.
• Simulation of two-dimensional axonal microtubule bundles subjected to suddenly applied end forces.
• Analysis of microtubule bundle deformation and failure under varying mechanical stresses.

Main Results:

• The model predicts critical regions within axonal microtubule bundles under tensile stress.
• Applied force rate and magnitude significantly affect microtubule bundle deformation.
• The study analyzes the nature of microtubular failure under different mechanical loads.

Conclusions:

• The developed model provides insights into the mechanical behavior of axonal microtubules under tension.
• Understanding these failure mechanisms is crucial for comprehending traumatic brain injury.
• This research highlights the role of tau protein in microtubule stability and response to mechanical stress.