Immunological Demyelination Triggers Macrophage/Microglial Cells Activation without Inducing Astrogliosis

Figure 1

Comparison of the expression of GFAP 7 days after a spinal cord stab injury to the dorsal column or after an injection of GalC antibodies plus complement proteins to the dorsal column. (a) The intensity of GFAP (green) immunoreactivity is low in the uninjured spinal cord dorsal column. (b) A dense ring of reactive astrocytes with intense GFAP (green) expression is evident surrounding the lesion “I.” (c) Higher magnification of the lesion edge: the double staining for GFAP and Hoechst reveals many reactive astrocytes tightly juxtaposed each other. (d) Eriochrome cyanine R staining showing the region of immunological demyelination. (e) GFAP (green) staining of a serial section to (d). (f) Higher magnification view within the region of demyelination showing double staining of GFAP (green) and Hoechst (blue). Note the presence of GFAP positive astrocytes (arrows) close to the edge of immunological demyelination region (white*). (g) GFAP positive astrocytes (arrows) deeper within the region of demyelination. Note the absence of reactive astrocytes at the border zone between normally myelinated and demyelinated area. (h) Higher magnification within the region of demyelination: the double staining for GFAP and Hoechst reveals an astrocyte (arrow) and multiple intermediate GFAP filaments (arrow heads). (i) The numbers of GFAP-positive cells within regions of immunological demyelination were similar compared to those within regions of normal dorsal column. Scale bars: (a) and (b) 100 μm; (d), (e), and (g) 50 μm; (c), (f), and (h) 16.6 μm.