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Myelin galactolipids: Mediators of axon‐glial interactions?
Author(s) -
Popko Brian
Publication year - 2000
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/(sici)1098-1136(20000115)29:2<149::aid-glia8>3.0.co;2-4
Subject(s) - axon , myelin , galactolipid , galactolipids , biology , node of ranvier , neuroscience , axon hillock , neuroglia , microbiology and biotechnology , oligodendrocyte , myelin sheath , anatomy , central nervous system , biochemistry , membrane , phospholipid , chloroplast , gene
The precise alignment of myelin segments along the length of the axon is essential for the saltatory propagation of an electrical impulse. Furthermore, node of Ranvier formation and function are dependent on the proper interactions between myelinating glial cells and the axon. Nevertheless, the molecules that regulate the placement and association of myelinating cells with axons remain largely unidentified. Recently, however, the analysis of mutant mice incapable of synthesizing the galactolipids of myelin has revealed defects in these processes. The galactolipid‐deficient mice display alterations in the spacing of internodal segments along the axon: large unmyelinated gaps are common and overlapping myelin segments are observed. Moreover, the normal tight association between the lateral loops of the myelinating cell and the axonal membrane at the paranode region is also disrupted in these animals. Strikingly, there is a complete absence of transverse bands at the axon‐glial junction, with the lateral loops frequently turning away from the axon. These data indicate that the galactolipids play an essential role in axon‐glial interactions and node of Ranvier formation. GLIA 29:149–153, 2000. © 2000 Wiley‐Liss, Inc.