Fig. 4.
Effect of glial-conditional Aqp4 deletion on brain water content and blood–brain barrier permeability. (A) Increase in brain water content 40 min after i.p. water injection (150 mL/kg) was significantly lower in cAqp4−/− mice than in f/f litter controls. Error bars indicate SE. (B) Basal brain water content of cAqp4−/− mice was significantly higher than that of WT and f/f controls, but did not differ from that of constitutive Aqp4−/− mice. (C) Brain mass did not differ significantly between genotypes (P > 0.05). (D) Baseline water content of forebrain hemispheres and brainstem was higher in cAQP4−/− mice than in controls. (E) Baseline brain water content at various stages of postnatal development. At postnatal days 1 (P1) and 8 (P8) the genotypes did not differ. At P15, P28, and P70, the brain water content of cAqp4−/− mice was significantly higher than that of f/f mice. (F) Blood–brain barrier macromolecule permeability. Evans blue staining was not observed in f/f or cAqp4−/− mouse brains subsequent to i.v. injection. No significant difference was observed in mean Evans blue content between the two genotypes.