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Updated: May 19, 2026
Measurement of Tension Release During Laser Induced Axon Lesion to Evaluate Axonal Adhesion to the Substrate at Piconewton and Millisecond Resolution
Published on: May 27, 2013
Atomic force microscopy reveals important differences in axonal resistance to injury
Margaret H Magdesian1, Fernando S Sanchez2, Monserratt Lopez3
1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Program in NeuroEngineering, McGill University, Montreal, Quebec, Canada; Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Researchers determined the pressure thresholds for axonal injury. Hippocampal axons tolerated 65 Pa, while dorsal root ganglia axons withstood 540 Pa, revealing differences in mechanical susceptibility.
Area of Science:
- Neuroscience
- Biophysics
- Cell Biology
Background:
- Axonal degeneration following traumatic brain injury and nerve compression causes significant disability.
- Understanding axonal response to mechanical injury is crucial for developing treatments.
- Current methods limit the evaluation of individual axon responses to injury.
Purpose of the Study:
- To determine the pressure thresholds for axonal transport disruption and axonal survival.
- To investigate the differential susceptibility of various axon types to mechanical injury.
- To explore the role of axonal cytoskeleton and elasticity in injury response.
Main Methods:
- Combination of microfluidics, atomic force microscopy, and in vivo imaging.
- Estimation of threshold forces for uncoupling axonal transport and compromising axonal survival.
- Measurement of elastic modulus of live axons.
Main Results:
- Rat hippocampal axons recovered transport at pressures up to 65 ± 30 Pa.
- Dorsal root ganglia axons resisted pressures up to 540 ± 220 Pa.
- Dorsal root ganglia axons exhibited a 20% lower elastic modulus than hippocampal axons.
Conclusions:
- Axonal cytoskeleton integrity is critical for determining axonal fate after injury.
- Differential elasticity contributes to varying susceptibility of axons to mechanical stress.
- Findings offer new strategies for improving injury diagnosis and developing neuroprotective methods.
