Fig. 3

Astrocyte activation. a GFAP/collagen IV double immunofluorescence labeled astrocytes (GFAP, red) and microvessel basal lamina (collagen IV, green) in the cerebral cortex and white matter of saline- and LPS-exposed animals [× 10 magnification (top row) and × 20 magnification (bottom row), scale bar = 100 μm; nuclear counterstaining DAPI (blue)]. White arrows indicate GFAP-positive cells (a). b represent the quantification of GFAP immunoreactivity in the cerebral cortex and white matter of the saline- and LPS-exposed fetal sheep. GFAP expression as the percent of the area of the fields (total area) segmented on anti-GFAP-stained sections in the saline- and LPS-exposed groups. An average of 15–20 fields per region and per animal and n = 8 in the saline-exposed group and n = 7 in the LPS-exposed group were analyzed. Statistical analysis by Kruskal-Wallis test followed by Dunn’s post hoc test, **P < 0.01. c Correlations between perivascular astrocytes profiles and microvessel density in the cerebral cortex and white matter of the fetal ovine brain. GFAP expression profiles plotted on the y-axis against the collagen type IV expression as the vascular density in cerebral cortex (r = 0.073, n = 15, P = 0.80) and white matter (r = 0.59, n = 15, P = 0.02). Solid line is the regression line. Dashed lines are the 95% confidence intervals