title: Activity-dependent regulation of myelin maintenance in the adult rat.
abstract: Hindlimb unloading (HU) is known to induce changes in the neuromuscular system. However, no data describing the effects of HU on morphological characteristics of peripheral nerve have been reported so far. Therefore, we used soleus and radial nerves obtained from control and rats submitted to 14 days of HU to study the consequences of a decrease (soleus) or an increase (radial) in neural activity on its morphology. The mean number of fibers was not changed after HU. The soleus nerve axon diameter was weakly affected after HU, whereas the myelin thickness was reduced. For the radial nerve, both axon and fiber diameter were increased, and the myelin thickness and internodal distance were higher in HU rats. These results suggest that regulation of myelin maintenance undergoes plastic mechanisms. Neural activity and/or neural pattern might be essential in the maintenance of myelin sheath in adults.
authors.affiliation: Laboratoire de Plasticité Neuromusculaire, EA 4345, IFR 147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq cedex, France. marie-helene.canu@univ-lille1.fr
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Canu
authors.forename: Michèle
authors.initials: M
authors.lastname: Carnaud
authors.forename: Florence
authors.initials: F
authors.lastname: Picquet
authors.forename: Laurence
authors.initials: L
authors.lastname: Goutebroze
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D019417:Hindlimb Suspension / Q000502:physiology; D008297:Male; D008856:Microscopy, Fluorescence; D009043:Motor Activity / Q000502:physiology*; D009186:Myelin Sheath / Q000502:physiology / Q000648:ultrastructure; D009413:Nerve Fibers, Myelinated / Q000502:physiology* / Q000648:ultrastructure; D009431:Neural Conduction; D009473:Neuronal Plasticity; D010525:Peripheral Nerves / Q000502:physiology* / Q000648:ultrastructure; D011826:Radial Nerve / Q000502:physiology / Q000648:ultrastructure; D011901:Ranvier's Nodes / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar