Figure 3.

In vivo 2-photon imaging showing Slit2 maintains integrity of the BBB in aging mice. (A) 3D image stacks of the dynamic change of permeability of the BBB revealed by in vivo 2-photon microscopy following intravenous injection of dextran rhodamine B (red, 40 kDa). Magnification, ×250; scale bar=200 µm. (B) Accumulation of rhodamine B around blood vessels of the brain parenchyma was evaluated by in vivo 2-photon microscopy (magnification, ×250; scale bar=200 µm). (C) Quantitative analysis of the fluorescence intensity of rhodamine B. Each dataset is expressed as the mean ± standard deviation. (^*P<0.05 and ^**P<0.01, vs. Slit-Tg; n=6 per group.). Slit2, slit guidance ligand 2; Tg, transgenic; WT, wild-type; BBB, blood-brain barrier