I. Permeability assay using vibratome section showing the leakage of retro-orbital injected cadaverine dye (red) in the brain of WT (top panel) and Glut1iECKO (bottom panel) mice. Note that cadaverine is retained in the intravascular area of WT mice (upper panel), but extravasated and accumulated in the brain parenchyma (white arrowheads) of Glut1iECKO (bottom panel) mice. 