Fig. 2

FM1-43 probe diffuses at a faster rate from the luminal to abluminal walls of endothelial cells in Tg2576 mouse brain tissue. a, MIPs of venules perfused with FM1-43 for 10 min in WT and Tg2576 mouse brains demonstrating the outlined ECs across the walls. b, A capillary in a WT cortical slice perfused with FM1-43 at 2 and 10 min (left) and the corresponding spatial fluorescence profiles (right) of a line profile (grey line, 5-µm thick) across the capillary wall normalized to the intravascular fluorescence. After 2 min, only the luminal membrane is stained (i), while the labeling of the abluminal membrane (ii) can be detected after 10 min. The LUT ‘royal’ is a color map that codes low-intensity pixels ‘blue’ and high-intensity pixels as ‘white’. c, A capillary in a Tg2576 cortical slice recorded at t₂ and t₁₀ (left) and the corresponding spatial fluorescence profiles (right) of a line profile normalized to the intravascular fluorescence. The labelling of the abluminal membrane can be detected at as early as 2 min after starting the FM1-43 perfusion, which intensifies over time (ii). d, Quantified fluorescence intensities within the abluminal membranes of capillaries in WT (n_ROI=8) and Tg2576 (n_ROI=8) mice. After 10 min, the diffused FM1-43 to the abluminal membranes in Tg2576 mice was 1.7-fold higher than in WT mice (Student’s t-test, *P < 0.05). The measured intensities were background-corrected and normalized to the corresponding luminal fluorescence intensities. Data are represented as mean ± SEM, obtained from 17 injections/5 animals