title: Vibrational spectroscopic imaging and multiphoton microscopy of spinal cord injury.
abstract: Spinal cord injury triggers a series of complex biochemical alterations of nervous tissue. Up to now, such cellular events could not be studied without conventional tissue staining. The development of optical, label-free imaging techniques could provide powerful monitoring tools with the potential to be applied in vivo. In this work, we assess the ability of vibrational spectroscopy to generate contrast at molecular level between normal and altered regions in a rat model of spinal cord injury. Using tissue sections, we demonstrate that Fourier transform infrared (FT-IR) spectroscopy and spontaneous Raman spectroscopy are able to identify the lesion, the surrounding scar, and unharmed normal tissue, delivering insight into the biochemical events induced by the injury and allowing mapping of tissue degeneration. The FT-IR and Raman spectroscopic imaging provides the basis for fast multimodal nonlinear optical microscopy (coherent anti-Stokes Raman scattering, endogenous two-photon fluorescence, and second harmonic generation). The latter proves to be a fast tool for imaging of the lesion on unstained tissue samples, based on the alteration in lipid content, extracellular matrix composition, and microglia/macrophages distribution pattern. The results establish these technologies in the field of regeneration in central nervous system, with the long-term goal to extend them to intravital use, where fast and nonharmful imaging is required.
authors.affiliation: Clinical Sensing and Monitoring, Faculty of Medicine, Carl Gustav Carus University Hospital, Dresden University of Technology, Fetscherstrasse 74, D-01307 Dresden, Germany. Roberta.Galli@tu-dresden.de
authors.forename: Roberta
authors.initials: R
authors.lastname: Galli
authors.forename: Ortrud
authors.initials: O
authors.lastname: Uckermann
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Winterhalder
authors.forename: Kerim H
authors.initials: KH
authors.lastname: Sitoci-Ficici
authors.forename: Kathrin D
authors.initials: KD
authors.lastname: Geiger
authors.forename: Edmund
authors.initials: E
authors.lastname: Koch
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schackert
authors.forename: Andreas
authors.initials: A
authors.lastname: Zumbusch
authors.forename: Gerald
authors.initials: G
authors.lastname: Steiner
authors.forename: Matthias
authors.initials: M
authors.lastname: Kirsch
mesh_terms: D000818:Animals; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013116:Spinal Cord / Q000473:pathology*; D013119:Spinal Cord Injuries / Q000473:pathology*