Early Ultrastructural Defects of Axons and Axon-Glia Junctions in Mice Lacking Expression of Cnp1

Edgar, J.M. , McLaughlin, M. , Werner, H.B., McCulloch, M.C., Barrie, J.A., Brown, A., Faichney, A., Snaidero, N., Nave, K.A. and Griffiths, I.R. (2009) Early Ultrastructural Defects of Axons and Axon-Glia Junctions in Mice Lacking Expression of Cnp1. Glia, 57(16), pp. 1815-1824. (doi: 10.1002/glia.20893)

Full text not currently available from Enlighten.

Abstract

Most axons in the central nervous system (CNS) are surrounded by a multilayered myelin sheath that promotes fast, saltatory conduction of electrical impulses. By insulating the axon, myelin also shields the axoplasm from the extracellular milieu. In the CNS, oligodendrocytes provide support for the long-term maintenance of myelinated axons, independent of the myelin sheath. Here, we use electron microscopy and morphometric analyses to examine the evolution of axonal and oligodendroglial changes in mice deficient in 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) and in mice deficient in both CNP and proteolipid protein (PLP/DM20). We show that CNP is necessary for the formation of a normal inner tongue process of oligodendrocytes that myelinate small diameter axons. We also show that axonal degeneration in Cnp1 null mice is present very early in postnatal life. Importantly, compact myelin formed by transplanted Cnp1 null oligodendrocytes induces the same degenerative changes in shiverer axons that normally are dysmyelinated but structurally intact. Mice deficient in both CNP and PLP develop a more severe axonal phenotype than either single mutant, indicating that the two oligodendroglial proteins serve distinct functions in supporting the myelinated axon. These observations support a model in which the trophic functions of oligodendrocytes serve to offset the physical shielding of axons by myelin membranes.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Barrie, Mrs Jennifer and Griffiths, Prof Ian and McLaughlin, Dr Mark and Edgar, Professor Julia and McCulloch, Mrs Maj-Lis
Authors: Edgar, J.M., McLaughlin, M., Werner, H.B., McCulloch, M.C., Barrie, J.A., Brown, A., Faichney, A., Snaidero, N., Nave, K.A., and Griffiths, I.R.
College/School:College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Glia
ISSN:0894-1491

University Staff: Request a correction | Enlighten Editors: Update this record