title: Rewiring of hindlimb corticospinal neurons after spinal cord injury.
abstract: Little is known about the functional role of axotomized cortical neurons that survive spinal cord injury. Large thoracic spinal cord injuries in adult rats result in impairments of hindlimb function. Using retrograde tracers, we found that axotomized corticospinal axons from the hindlimb sensorimotor cortex sprouted in the cervical spinal cord. Mapping of these neurons revealed the emergence of a new forelimb corticospinal projection from the rostral part of the former hindlimb cortex. Voltage-sensitive dye (VSD) imaging and blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI) revealed a stable expansion of the forelimb sensory map, covering in particular the former hindlimb cortex containing the rewired neurons. Therefore, axotomized hindlimb corticospinal neurons can be incorporated into the sensorimotor circuits of the unaffected forelimb.
authors.affiliation: Brain Research Institute, University of Zurich and Swiss Federal Institute of Technology Zurich, Zurich, Switzerland. arko@ini.phys.ethz.ch
authors.forename: Arko
authors.initials: A
authors.lastname: Ghosh
authors.forename: Florent
authors.initials: F
authors.lastname: Haiss
authors.forename: Esther
authors.initials: E
authors.lastname: Sydekum
authors.forename: Regula
authors.initials: R
authors.lastname: Schneider
authors.forename: Miriam
authors.initials: M
authors.lastname: Gullo
authors.forename: Matthias T
authors.initials: MT
authors.lastname: Wyss
authors.forename: Thomas
authors.initials: T
authors.lastname: Mueggler
authors.forename: Christof
authors.initials: C
authors.lastname: Baltes
authors.forename: Markus
authors.initials: M
authors.lastname: Rudin
authors.forename: Bruno
authors.initials: B
authors.lastname: Weber
authors.forename: Martin E
authors.initials: ME
authors.lastname: Schwab
mesh_terms: D000818:Animals; D019771:Axotomy / Q000379:methods; D001522:Behavior, Animal; D001931:Brain Mapping; D002574:Cervical Vertebrae; D004195:Disease Models, Animal; D005260:Female; D005456:Fluorescent Dyes; D005552:Forelimb / Q000503:physiopathology; D006614:Hindlimb / Q000503:physiopathology*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008564:Membrane Potentials / Q000502:physiology; D009044:Motor Cortex / Q000098:blood supply / Q000503:physiopathology; D009416:Nerve Regeneration / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D011712:Pyramidal Tracts / Q000098:blood supply / Q000473:pathology*; D011720:Pyrazoles; D051381:Rats; D011917:Rats, Inbred Lew; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000503:physiopathology*; D018709:Statistics, Nonparametric; D013844:Thiazoles
chemical_list: D005456:Fluorescent Dyes; D011720:Pyrazoles; C471342:RH1691; D013844:Thiazoles; D010100:Oxygen