Fig. 9

Optic nerve pathology began near the perimeter and blood vessels and progressed into the center. In the optic nerve a-b, the fibres that surround the axon bundles appear to be disrupted by 11 days post immunisation (dpi) in EAE mice. a There was also a reduction in the number of axons present in EAE mice compared to healthy controls at 11 dpi and 28 dpi in the optic nerve. b In the longitudinal optic nerve sections, an overall disruption of axonal organisation was observed in EAE mice. c-e Scanning electron micrographs of cross-sectional optic nerves in healthy and EAE mice provide a closer look. c In central sections, signs of axonal degeneration were first observed 11 dpi, while at 28 dpi severe pathology was present throughout the entire optic nerve. d Near the perimeter of the optic nerve sections, strong axonal degeneration was observed at both 11 and 28 dpi in EAE mice compared to healthy controls. Severe loss of axons and large empty spaces were also observed at 28 dpi near the perimeter of the optic nerve. e Some demyelinated axons were observed along with axonal degeneration at 11 dpi near blood vessels, while at 28 dpi severe axonal loss was present in EAE mice compared to healthy controls. Red arrows: demyelinated axons, DA: degenerating axon, E: empty myelin sheath with no axon, Oligo: oligodendrocyte, EAE: experimental autoimmune encephalomyelitis. Electron micrograph image resolution: 8 nm/pixel