title: Live animal myelin histomorphometry of the spinal cord with video-rate multimodal nonlinear microendoscopy.
abstract: In vivo imaging of cellular dynamics can be dramatically enabling to understand the pathophysiology of nervous system diseases. To fully exploit the power of this approach, the main challenges have been to minimize invasiveness and maximize the number of concurrent optical signals that can be combined to probe the interplay between multiple cellular processes. Label-free coherent anti-Stokes Raman scattering (CARS) microscopy, for example, can be used to follow demyelination in neurodegenerative diseases or after trauma, but myelin imaging alone is not sufficient to understand the complex sequence of events that leads to the appearance of lesions in the white matter. A commercially available microendoscope is used here to achieve minimally invasive, video-rate multimodal nonlinear imaging of cellular processes in live mouse spinal cord. The system allows for simultaneous CARS imaging of myelin sheaths and two-photon excitation fluorescence microendoscopy of microglial cells and axons. Morphometric data extraction at high spatial resolution is also described, with a technique for reducing motion-related imaging artifacts. Despite its small diameter, the microendoscope enables high speed multimodal imaging over wide areas of tissue, yet at resolution sufficient to quantify subtle differences in myelin thickness and microglial motility.
authors.affiliation: Université Laval, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, Canada.
authors.forename: Erik
authors.initials: E
authors.lastname: Bélanger
authors.forename: Joël
authors.initials: J
authors.lastname: Crépeau
authors.forename: Sophie
authors.initials: S
authors.lastname: Laffray
authors.forename: Réal
authors.initials: R
authors.lastname: Vallée
authors.forename: Yves
authors.initials: Y
authors.lastname: De Koninck
authors.forename: Daniel
authors.initials: D
authors.lastname: Côté
mesh_terms: D000818:Animals; D019723:Endoscopes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D018715:Microscopy, Video / Q000295:instrumentation*; D009186:Myelin Sheath / Q000378:metabolism*; D017711:Nonlinear Dynamics; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D013116:Spinal Cord / Q000166:cytology* / Q000378:metabolism*; D014018:Tissue Distribution