title: Single myelin fiber imaging in living rodents without labeling by deep optical coherence microscopy.
abstract: Myelin sheath disruption is responsible for multiple neuropathies in the central and peripheral nervous system. Myelin imaging has thus become an important diagnosis tool. However, in vivo imaging has been limited to either low-resolution techniques unable to resolve individual fibers or to low-penetration imaging of single fibers, which cannot provide quantitative information about large volumes of tissue, as required for diagnostic purposes. Here, we perform myelin imaging without labeling and at micron-scale resolution with >300-μm penetration depth on living rodents. This was achieved with a prototype [termed deep optical coherence microscopy (deep-OCM)] of a high-numerical aperture infrared full-field optical coherence microscope, which includes aberration correction for the compensation of refractive index mismatch and high-frame-rate interferometric measurements. We were able to measure the density of individual myelinated fibers in the rat cortex over a large volume of gray matter. In the peripheral nervous system, deep-OCM allows, after minor surgery, in situ imaging of single myelinated fibers over a large fraction of the sciatic nerve. This allows quantitative comparison of normal and Krox20 mutant mice, in which myelination in the peripheral nervous system is impaired. This opens promising perspectives for myelin chronic imaging in demyelinating diseases and for minimally invasive medical diagnosis.
authors: Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS 46 rue d'Ulm, Paris 75005 [corrected] France.
authors: Juliette
authors: J
authors: Ben Arous
authors: Jonas
authors: J
authors: Binding
authors: Jean-François
authors: JF
authors: Léger
authors: Mariano
authors: M
authors: Casado
authors: Piotr
authors: P
authors: Topilko
authors: Sylvain
authors: S
authors: Gigan
authors: A Claude
authors: AC
authors: Boccara
authors: Laurent
authors: L
authors: Bourdieu
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000737:chemistry / Q000648:ultrastructure; D051767:Early Growth Response Protein 2 / Q000235:genetics; D005260:Female; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008853:Microscopy; D057054:Molecular Imaging / Q000379:methods*; D009186:Myelin Sheath / Q000737:chemistry* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000737:chemistry / Q000648:ultrastructure; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D051767:Early Growth Response Protein 2