Figure 8

Combined aquaporin-4 immunofluorescence and flouorescein linked lectin staining in control and two week hydrocephalic rat. Aquaporin-4 visualized with TxRED (red) and lectin with FITC (green). Nuclear counterstaining with DAPI (blue). Pictures represent glia limitans (A-F), ependyma (G-L) and vessels (M-R). In both contol and hydrocephalic rats aquaporin-4 and lectin staining showed complementary immunoreactivity, clearly not co-localized in glia limitans (A-F). In the ependyma lectin intensively stained the apical membrane of the cells bordering the ventricular wall (H, I, K, L). Immunoreactivity of aquaporin-4 in controls clearly localised to the basolateral membrane (G). In hydrocephalic animals presenting changed aquaporin-4 morphology of the ependyma (J-L), the aquaporin-4 immunoreactivity of the cells lining the ventricle was found not to co-localize with the continuous apical staining of the ependymal cells by lectin (K), except in specific areas corresponding to the lateral membrane of the ependymal cells (arrows, K). This confirmed basolateral expression of aquaporin-4 in the ependymal cells of hydrocephalic rats. In vessels (M-R) aquaporin-4 was clearly located to perivascular areas without signs of endothelial expression. No evidence of aquaporin-4 expression in microglia was found; neither in controls nor in hydrocephalic rats. * = lateral ventricle. Scale bar 50 μm.