title: Multimodal coherent anti-Stokes Raman scattering microscopy reveals microglia-associated myelin and axonal dysfunction in multiple sclerosis-like lesions in mice.
abstract: Myelin loss and axonal degeneration predominate in many neurological disorders; however, methods to visualize them simultaneously in live tissue are unavailable. We describe a new imaging strategy combining video rate reflectance and fluorescence confocal imaging with coherent anti-Stokes Raman scattering (CARS) microscopy tuned to CH(2) vibration of myelin lipids, applied in live tissue of animals with chronic experimental autoimmune encephalomyelitis (EAE). Our method allows monitoring over time of demyelination and neurodegeneration in brain slices with high spatial resolution and signal-to-noise ratio. Local areas of severe loss of lipid signal indicative of demyelination and loss of the reflectance signal from axons were seen in the corpus callosum and spinal cord of EAE animals. Even in myelinated areas of EAE mice, the intensity of myelin lipid signals is significantly reduced. Using heterozygous knock-in mice in which green fluorescent protein replaces the CX(3)CR1 coding sequence that labels central nervous system microglia, we find areas of activated microglia colocalized with areas of altered reflectance and CARS signals reflecting axonal injury and demyelination. Our data demonstrate the use of multimodal CARS microscopy for characterization of demyelinating and neurodegenerative pathology in a mouse model of multiple sclerosis, and further confirm the critical role of microglia in chronic inflammatory neurodegeneration.
authors.affiliation: Brigham and Women's Hospital, Center for Neurologic Diseases, Partner Multiple Sclerosis Center, Harvard Medical School, Department of Neurology, Boston, Massachusetts 02115, USA.
authors.forename: Jaime
authors.initials: J
authors.lastname: Imitola
authors.forename: Daniel
authors.initials: D
authors.lastname: Côté
authors.forename: Stine
authors.initials: S
authors.lastname: Rasmussen
authors.forename: X Sunney
authors.initials: XS
authors.lastname: Xie
authors.forename: Yingru
authors.initials: Y
authors.lastname: Liu
authors.forename: Tanuja
authors.initials: T
authors.lastname: Chitnis
authors.forename: Richard L
authors.initials: RL
authors.lastname: Sidman
authors.forename: Charles P
authors.initials: CP
authors.lastname: Lin
authors.forename: Samia J
authors.initials: SJ
authors.lastname: Khoury
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology*; D051379:Mice; D008853:Microscopy / Q000379:methods*; D009103:Multiple Sclerosis / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D013059:Spectrum Analysis, Raman / Q000379:methods*