Fig. 3

Lack of EphB2 ameliorates brain edema following acute stroke by diminishing formation of cytotoxic edema. a WT and Ephb2^−/− mice underwent 60 min MCAO followed by 6 or 24 h of reperfusion. Brain sections were subjected to immunofluorescent staining of CD31 and ZO-1 to visualize interendothelial tight junctions. For each mouse disruptions (gaps; denoted by white arrowhead) of the regular ZO-1 localization pattern were counted in 10–30 randomly chosen microvessels localized within the ipsilesional striatum (infarct core) and cortex (periinfarct), respectively (mean ± SD; n = 4/4, n = 4/4; Two-way ANOVA with Holm-Sidak’s multiple comparisons test). Scale bar = 10 μm. b WT and Ephb2^−/− mice were subjected to 60 min MCAO followed by 12 or 24 h of reperfusion. Evans Blue was applied by tail vein injection 2 h before end of the experiment. After transcardial perfusion the amount of Evans Blue was quantified within contra- and ipsilateral brain hemisphere using absorption spectroscopy (mean ± SD; n = 3/4, n = 9/8; Two-way ANOVA with Holm-Sidak’s multiple comparisons test). c, d WT and Ephb2^−/− mice were subjected to 60 min MCAO followed by 24 h of reperfusion. High-field (9.4 T) in vivo MRI was applied to monitor spatiotemporal development of vasogenic (T2-weighted imaging) and cytotoxic (ADC maps derived from diffusion-weighted imaging) edema post-stroke. Representative brain T2- and diffusion-weighted images of WT and Ephb2^−/− mice in coronal planes are depicted in (c). d shows quantification of the ischemic lesion volume on T2 and ADC maps in basal ganglia (single values and mean ± SD; n = 9/8; Two-way ANOVA with Holm-Sidak’s multiple comparisons test). * p < 0.05