Label-free in vivo imaging of myelinated axons in health and disease with spectral confocal reflectance microscopy

Nat Med. 2014 Apr;20(4):443-9. doi: 10.1038/nm.3495. Epub 2014 Mar 30.


We report a newly developed technique for high-resolution in vivo imaging of myelinated axons in the brain, spinal cord and peripheral nerve that requires no fluorescent labeling. This method, based on spectral confocal reflectance microscopy (SCoRe), uses a conventional laser-scanning confocal system to generate images by merging the simultaneously reflected signals from multiple lasers of different wavelengths. Striking color patterns unique to individual myelinated fibers are generated that facilitate their tracing in dense axonal areas. These patterns highlight nodes of Ranvier and Schmidt-Lanterman incisures and can be used to detect various myelin pathologies. Using SCoRe we carried out chronic brain imaging up to 400 μm deep, capturing de novo myelination of mouse cortical axons in vivo. We also established the feasibility of imaging myelinated axons in the human cerebral cortex. SCoRe adds a powerful component to the evolving toolbox for imaging myelination in living animals and potentially in humans.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / pathology*
  • Brain / pathology
  • Humans
  • Mice
  • Microscopy, Confocal / methods*
  • Microscopy, Interference / methods*
  • Myelin Sheath / pathology*
  • Nerve Fibers, Myelinated / pathology*
  • Peripheral Nerves / pathology
  • Spinal Cord / pathology