Effects of nerve bundle geometry on neurotrauma evaluation

Area of Science:

• Neuroscience
• Biophysics
• Computational Biology

Background:

• Alterations in neuron structure can lead to nervous system signal propagation abnormalities, as seen in brain damage.
• Understanding how mechanical changes affect nerve fibers is crucial for diagnosing and treating neurological conditions.

Purpose of the Study:

• To investigate the effects of geometrical changes and damage on nerve bundles.
• To compare the mechanical and electrical responses of myelinated and unmyelinated nerve fibers.

Main Methods:

• Developed a 3D finite element model of nerve bundles with electromechanical coupling and modulated spiking activation.
• Simulated mechanical compression and tension to induce membrane damage in 4-fiber nerve bundles.
• Analyzed changes in strain and neural activity for intact and damaged nerve membranes.

Main Results:

• Unmyelinated fibers exhibited lower strain and electrophysiological impairments than myelinated fibers.
• Larger nerve bundles showed higher deformation levels but smaller bundles experienced greater electrophysiological impairments.
• Smaller nerve fibers tolerated higher elongation before mechanical failure.

Conclusions:

• The myelin sheath restricts membrane deformation and disperses plastic strains.
• Bundle size influences deformation and electrophysiological impairment levels.
• Nerve fiber structure and size are critical factors in mechanical stress tolerance and signal integrity.