FIGURE 4

Telomerase depletion is associated with increased BBB permeability with ageing in the zebrafish brain. (A) Schematic figure of the BBB permeability assay. Dextran‐FITC 4 kDa or vehicle control (HBSS) were injected by intraperitoneal injection. 3 h later the brains were dissected and imaged in the Odyssey CLx (Li‐cor) to confirm the presence of Dextran‐FITC. Quantification of the green fluorescence in the fish brains shows higher FITC expression in old WT (> 30 months) compared to middle aged ones (9–16 months). This increased presence of dextran‐FITC in tert^−/− is already observed at 9–16 months, overall suggesting that there is increased brain permeability with natural ageing and that this is anticipated in the absence of telomerase. N = 9–20 per group in the tested animals; N = 3–6 per group in the vehicle control animals. Bar errors represent the SEM. Statistics: Unpaired t‐tests. *p < 0.05; ***p < 0.001.