Disruption of the gene for the myelin-associated glycoprotein improves axonal regrowth along myelin in C57BL/Wlds mice.
The myelin-associated glycoprotein (MAG) has been shown to be inhibitory for certain neurons in vitro (Mukhopadhyay et al., 1994; McKerracher et al., 1994). To investigate whether MAG is an inhibitory component in peripheral myelin in vivo, MAG-deficient mutant mice were cross-bred with C57BL/Wlds mice that have delayed lesion-induced myelin degeneration and axon regrowth. While in crushed nerves of C57BL/Wlds mice expressing MAG, only 16% of myelin sheaths were associated with regrowing axons, this number was doubled in MAG-deficient C57BL/Wlds mice. These observations suggest that the absence of MAG may contribute to the improved axonal regrowth in the double mutants. Therefore, degeneration of MAG-containing myelin might be an important prerequisite to optimize axonal regrowth after peripheral nerve injury.
Schäfer
M
M
Department of Neurobiology, Swiss Federal Institute of Technology, Zürich, Switzerland.
Fruttiger
M
M
Montag
D
D
Schachner
M
M
Martini
R
R
D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D005796:Genes / Q000235:genetics*; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D018992:Myelin-Associated Glycoprotein / Q000235:genetics*
D018992:Myelin-Associated Glycoprotein