Figure 4.

Sv/sv mice display astrogliosis throughout the brain. (A) Western blots of sv/wt, sv/sv, and sh1/sh1 brain homogenates, equal protein loaded, reveal that GFAP is increased fourfold in sv/sv versus sv/wt brain. Densitometric analysis compared the ratios of GFAP to actin between samples. Lanes between those shown were omitted. (B and C) Sv/sv, sv/wt, and sh1/sh1 brain sections were incubated with anti-GFAP, and either peroxidase- (B) or fluorescence (C)-conjugated secondary antibody. Representative images of cerebellum (B) and hippocampus (C) depict the greater GFAP immunoreactivity seen in sv/sv versus sv/wt and sh1/sh1 brains. Granule cell (B, GCL) and molecular layers (B, ML) of the cerebellum and area CA1 of the hippocampus (C) are labeled. Bars: (B) 0.25 mm; (C) 20 μm. Minimal contrast/brightness adjustment was performed. (D) Activated astrocyte exhibiting prominent gliofilaments (GF) characteristic of sv/sv neuropil. Swollen mitochondria (arrowheads) are seen in surrounding cells. Bar, 1 μm. (E) Cells isolated from sv/wt or sv/sv brains were analyzed by flow cytometry. Unstained cells (open peaks) were compared with labeled cells (shaded peaks) and used to determine background fluorescence (not within the GFAP+ region). (F) The proportion of cells within the GFAP+ range and the mean label intensity within this range were compared, and reveal that sv/sv mice have a 2.1-fold increase in GFAP+ astrocytes (*, P < 0.05, n = 4 each) per 100,000 cells and a 1.7-fold increase in GFAP per cell (*, P < 0.02, n = 4 each). Error bars indicate SEM.