Figure 6.

Loss of domain organization among hypertrophic astrocytes in other epilepsy models. A, Low- and high-power images of sensory-motor cortex 6 months after exposure to kainic acid. A clear upregulation of GFAP throughout the cortical layers is evident. Scale bars (SBs): left, 100 μm; right, 10 μm. B, Low- and high-power images of the sensory-motor cortex of the SWXL-4 mouse that also exhibited an increase in GFAP expression. SBs: left, 100 μm; right, 10 μm. C, D, Morphometric analysis in mice exposed to kainate (KA) and the SWXL-4 mice based on GFAP (KA, n = 65 cells, 3 mice; SWXL-4, n = 85 cells, 6 mice; mean ± SEM; *p < 0.001). E, Representative EEG recording of a mouse exposed to kainate 6 months earlier. F, EEG recording of SWXL-4 mice 10 months of age. G, Diolistic labeling revealed extensive overlap of processes between two reactive astrocytes in the cortex of a kainate-treated mouse. SB, 10 μm. Inset, Overlapping processes of two astrocytes in CA3. H, I, High-power images of blue box in G demonstrating overlapping area and processes of kainate-treated cortical astrocytes. J, Two adjacent astrocytes in SWXL-4 mice with overlapping domains. SB, 10 μm. K, L, High-power images of blue box in J demonstrating overlapping area and processes in SWXL-4 cortical astrocytes. M, Quantification of the change in volume in kainate-treated and SWXL-4 mice compared with control. There is a significant increase in volume of reactive astrocytes in both the kainate-treated and SWXL-4 mice compared with control (KA, n = 10, 3 mice; SWXL-4, n = 16, 6 mice; mean ± SEM; *p < 0.05). N, O, Quantification of loss of domain organization in the kainate-treated and SWXL-4 cortical astrocytes. There is a significant increase in the amount of overlap between astrocyte domains in both kainate-treated and SWXL-4 mice compared with control (KA, n = 16 cells, 4 mice; SWXL-4, n = 44 cells, 7 mice; mean ± SEM; *p < 0.001).