Fig. 2

Pericyte coverage surrounding the brain microvessels. Representative images of desmin/collagen type IV double immunofluorescence labeled pericytes (desmin, red) and vessel basal lamina (collagen type IV, green) in the cerebral cortex (a) and white matter (b) of saline-exposed (top row) and LPS-exposed (bottom row) animals ( ×40 magnification scale bar = 50 μm, nuclear counterstaining DAPI (blue)). The inset (× 10 magnification, scale bar = 100 μm) on each image identifies the area of the brain from which the image was taken. White arrows indicate pericyte vascular coverage, whereas white arrowheads indicate the microvessels that are not covered by pericytes. c Graphs represent the quantification pericyte coverage in the cerebral cortex and white matter of the saline- and LPS-exposed fetal sheep. Pericyte coverage expressed as the percent of positive desmin area overlapping with the vessel wall. 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 < 0.05; **P < 0.01. d Correlations between pericyte microvessel coverage and vessel density in the cerebral cortex and the white matter of the fetal ovine brain. Desmin vascular coverage plotted on the y-axis against the collagen type IV expression as the vascular density in the cerebral cortex (r = 0.68, n = 15, P = 0.0052) and white matter (r = 0.56, n = 15, P = 0.031). Solid line is the regression line. Dashed lines are the 95% confidence intervals