Quantitative analysis by in vivo imaging of the dynamics of vascular and axonal networks in injured mouse spinal cord.
Understanding the endogenous repair capacity of spinal cord is pivotal to develop strategies to improve it. Here we design a paradigm of spinal cord lesion in the dorsal column using a 2-photon microscopy technique to dynamically and chronically monitor simultaneous changes of vascular and axonal networks in living mice up to 4 months postinjury. High-resolution images showed that early explorative sprouting of surviving injured axons resulted in extensive regrowth until and past the lesion site within 2 months. Blood vessel density was transiently up-regulated and most neurovascular interactions occurred within 2 weeks. Time-lapse analysis showed that neovessels exerted a potent growth stimulating action, but no guidance effect on neighboring sprouts, possibly because of their geometry and plasticity. Nevertheless, if reconnection depends on axon sprout density, stimulation of angiogenesis would probably be beneficial to repair. More generally, this imaging approach is showing promise to aid in monitoring brain diseases and the efficacy of potential treatments.
Dray
Cyril
C
Unité Mixte de Recherche 6216, Centre National de la Recherche Scientifique, Université de la Méditerranée, Institut de Biologie du Développement de Marseille-Luminy, Parc Scientifique de Luminy, Marseille Cedex 9, France.
Rougon
Geneviève
G
Debarbieux
Franck
F
D000818:Animals; D001369:Axons / Q000473:pathology / Q000502:physiology*; D001808:Blood Vessels / Q000473:pathology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D009416:Nerve Regeneration; D013116:Spinal Cord / Q000473:pathology / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology*
D049452:Green Fluorescent Proteins