title: Reorganization of motor cortex and impairment of motor performance induced by hindlimb unloading are partially reversed by cortical IGF-1 administration.
abstract: Immobilization, bed rest, or sedentary lifestyle, are known to induce a profound impairment in sensorimotor performance. These alterations are due to a combination of peripheral and central factors. Previous data conducted on a rat model of disuse (hindlimb unloading, HU) have shown a profound reorganization of motor cortex and an impairment of motor performance. Recently, our interest was turned towards the role of insulin-like growth factor 1 (IGF-1) in cerebral plasticity since this growth factor is considered as the mediator of beneficial effects of exercise on the central nervous system, and its cortical level is decreased after a 14-day period of HU. In the present study, we attempted to determine whether a chronic subdural administration of IGF-1 in HU rats could prevent deleterious effects of HU on the motor cortex and on motor activity. We demonstrated that HU induces a shrinkage of hindlimb cortical representation and an increase in current threshold to elicit a movement. Administration of IGF-1 in HU rats partially reversed these changes. The functional evaluation revealed that IGF-1 prevents the decrease in spontaneous activity found in HU rats and the changes in hip kinematics during overground locomotion, but had no effect of challenged locomotion (ladder rung walking test). Taken together, these data clearly indicate the implication of IGF-1 in cortical plastic mechanisms and in behavioral alteration induced by a decreased in sensorimotor activity.
authors.affiliation: Univ. Lille, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Eurasport, 413 Rue Eugène Avinée, F-59120 Loos, France. Electronic address: j.mysoet@gmail.com.
authors.forename: Julien
authors.initials: J
authors.lastname: Mysoet
authors.affiliation: Univ. Lille, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Eurasport, 413 Rue Eugène Avinée, F-59120 Loos, France. Electronic address: marie-helene.canu@univ-lille1.fr.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Canu
authors.affiliation: Univ. Valenciennes, LAMIH UMR CNRS 8201 - Laboratory of Industrial and Human Automation control, Mechanical engineering and Computer Science, Le Mont Houy, F-59313 Valenciennes cedex 9, France. Electronic address: christophe.gillet@univ-valenciennes.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Gillet
authors.affiliation: Univ. Lille, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Eurasport, 413 Rue Eugène Avinée, F-59120 Loos, France. Electronic address: julie.fourneau@univ-lille1.fr.
authors.forename: Julie
authors.initials: J
authors.lastname: Fourneau
authors.affiliation: Univ. Valenciennes, LAMIH UMR CNRS 8201 - Laboratory of Industrial and Human Automation control, Mechanical engineering and Computer Science, Le Mont Houy, F-59313 Valenciennes cedex 9, France. Electronic address: cyril.garnier@univ-valenciennes.fr.
authors.forename: Cyril
authors.initials: C
authors.lastname: Garnier
authors.affiliation: Univ. Lille, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Eurasport, 413 Rue Eugène Avinée, F-59120 Loos, France. Electronic address: bruno.bastide@univ-lille1.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Bastide
authors.affiliation: Univ. Lille, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Eurasport, 413 Rue Eugène Avinée, F-59120 Loos, France. Electronic address: erwan.dupont@univ-lille1.fr.
authors.forename: Erwan
authors.initials: E
authors.lastname: Dupont
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000842:Ankle / Q000294:innervation; D001696:Biomechanical Phenomena; D016503:Drug Delivery Systems; D005552:Forelimb / Q000187:drug effects / Q000502:physiology; D006614:Hindlimb / Q000187:drug effects / Q000502:physiology; D019417:Hindlimb Suspension / Q000009:adverse effects*; D006615:Hip / Q000294:innervation; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D008124:Locomotion / Q000187:drug effects / Q000502:physiology; D008297:Male; D008565:Membrane Proteins; D009044:Motor Cortex / Q000187:drug effects* / Q000502:physiology*; D000068079:Motor Disorders / Q000188:drug therapy* / Q000209:etiology; D028044:Phosphate-Binding Proteins; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: C118719:ANKFY1 protein, human; D008565:Membrane Proteins; D028044:Phosphate-Binding Proteins; D007334:Insulin-Like Growth Factor I
keywords: Actimetry; Cortical plasticity; Disuse; Kinematics; Locomotion; Motor performance