Oligodendrocyte dynamics in the healthy adult CNS: evidence for myelin remodeling.
Bottom Line: We conclude that adult-born OLs in the optic nerve are engaged in myelin remodeling, either replacing OLs that die in service or intercalating among existing myelin sheaths.The latter would predict that average internode length should decrease with age.Consistent with that, we found that adult-born OLs elaborated much shorter but many more internodes than OLs generated during early postnatal life.
Affiliation: Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK.Show MeSH
Mentions: Although CC1 labeling demonstrates OL differentiation, it does not prove that those OLs form myelin sheaths. To identify newly formed myelinating OLs by morphology (Butt et al., 1994; McIver et al., 2005), we crossed Pdgfra-CreERT2 with Tau-mGFP reporter mice (Hippenmeyer et al., 2005). Tau-mGFP is active in neurons and OLs but not in OPs or other neural cells (Richter-Landsberg and Gorath, 1999) and is superior to Rosa-YFP for revealing OL morphology, either because the Tau promoter is more active than Rosa or because membrane-inserted green fluorescent protein (mGFP) is better than cytoplasmic YFP at revealing slender OL cell processes including the external tongue process, although it is still excluded from compact myelin (see Figure 7).
Affiliation: Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK.