Fig. 4

Disruption of astrocyte to oligodendrocyte GJs in inflamed spinal cord white matter (WM). a–f Fixed longitudinal spinal cord WM sections immunostained for astrocytic Cx43 (green) and Cx47 (red) with nuclear DAPI staining (blue) show reduced overall Cx43 immunoreactivity in LPS-injected spinal cord tissues (b, d, f) of all genotypes compared to saline controls (a, c, e). Fewer GJ plaques are formed by both Cx43 as well as Cx47 at oligodendrocyte cell bodies and proximal processes, which are often colocalized in control more than in LPS treated mice. In oligodendrocytes from LPS treated mice there is often a diffused signal of Cx47 intracellularly (inset in f). Scale bars in a–f: 10 μm. Counts of GJ plaques formed by Cx43 (g, I, k) as well as by Cx47 (h, j, l) confirm a significant reduction in LPS treated mice of all genotypes (Student’s t-test, *:p < 0.05, **:p < 0.01, ***:p < 0.001)