Assessment of axonal integrity within damaged myelin sheaths in TgPAC-Notch3
mice aged 20 months. (A-C) Representative electron micrographs of myelin sheaths containing either an apparently normal axon, although squashed against one side of the sheath (A) or a degenerating axon (B), and of an empty sheath with no axon (C). (D) Diagram showing that a similar proportion of abnormal myelin sheaths contains an apparently-intact axon (axon+) versus no or a degenerating axon (axon-) (n = 4 TgPAC-Notch3R169C mice). (E) Representative confocal image of fimbria double stained with SMI94 (red, MBP hyperintense foci) and C28E10 (green, axon) antibodies. Notice that acquisition parameters have been set to minimize visualization of normal myelin and maximize visualization of axon and myelin debris. (F-H) Red and green profiling of MBP hyperintense foci (red) with the axon (green) in a central position (F) (axon+) or in lateral position (G) (axon +) and foci with no axon (axon-) (H). (I) Diagram of the % of damaged myelin sheaths with axon (axon+) or without axon (axon-) (n = 5 TgPAC-Notch3R169C mice). Scale bar represents 0.6 μm (A, C), 0.5 μm (B) and 6.5 μm (E).