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Updated: Feb 17, 2026
A Versatile Murine Model of Subcortical White Matter Stroke for the Study of Axonal Degeneration and White Matter Neurobiology
Published on: March 17, 2016
Label-free tracking of subcortical white matter degradation in vivo using third harmonic generation microscopy in a
Nicole E Chernavsky1, Nuri Hong1, Lianne J Trigiani1
1Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
Abstract:
Characterization of myelin degradation in the white matter (WM) is important for understanding neurodegeneration. We demonstrate label-free in vivo imaging of myelin structure in the WM of mice, through intact cortex, using third harmonic generation (THG) microscopy at 1320-nm excitation. Longitudinal THG imaging of the same axons in the cuprizone mouse model of multiple sclerosis revealed dynamics of myelin blistering. Further, we measured intranodal distance at nodes of Ranvier in vivo and developed a novel metric of myelin structural change based on spatial concentration of the brightest THG signal. We also demonstrated compatibility with three-photon excited fluorescence microscopy by imaging GFP-labeled microglia in the WM in parallel with THG microscopy, thereby enabling detailed tracking of subcortical myelin and other cellular dynamics in neurodegenerative disease models.
Insights
This study introduces label-free in vivo imaging of white matter myelin using third harmonic generation (THG) microscopy. This technique visualizes myelin blistering and structural changes in neurodegenerative disease models.
Area of Science:
- Neuroscience
- Biomedical Optics
- Microscopy
Background:
- Myelin degradation in white matter (WM) is crucial for understanding neurodegeneration.
- Accurate characterization of myelin structure in vivo is essential for studying neurological diseases.
Purpose of the Study:
- To develop and demonstrate a label-free in vivo imaging method for myelin structure in mouse white matter.
- To investigate myelin dynamics and structural changes in a mouse model of multiple sclerosis.
- To enable simultaneous imaging of myelin and cellular activity in neurodegenerative disease models.
Main Methods:
- Utilized third harmonic generation (THG) microscopy with 1320-nm excitation for label-free in vivo imaging of myelin structure through the intact cortex.
- Performed longitudinal THG imaging on the same axons in the cuprizone mouse model.
- Measured intranodal distance at nodes of Ranvier in vivo.
- Developed a novel metric for myelin structural change based on THG signal concentration.
- Demonstrated compatibility with three-photon excited fluorescence microscopy for parallel imaging of GFP-labeled microglia.
Main Results:
- Successfully achieved label-free in vivo imaging of white matter myelin structure.
- Observed and characterized myelin blistering dynamics in the cuprizone model.
- Quantified intranodal distances and introduced a new metric for myelin structural integrity.
- Showcased parallel imaging of myelin (THG) and microglia (fluorescence) for comprehensive analysis.
Conclusions:
- THG microscopy provides a powerful label-free tool for in vivo characterization of white matter myelin structure and dynamics.
- This technique facilitates the study of myelin pathologies in neurodegenerative diseases.
- The combined THG and fluorescence imaging approach allows for simultaneous tracking of myelin and cellular changes in vivo.
