Fig. 3

ApoE periarterial inflow using in vivo 2-photon imaging (a) Pial surface arterial vessels showing apoE3-FITC within the perivascular space of arteries. b-g ApoE3-FITC along the perivascular space of penetrating arterial vessel at various depths below the brain surface. h Magnified image of the white boxed area in (panel b) (scale bar 50 μm). Following intracisternal injection (5 μL at 1 μL/min) of apoE3-FITC images were acquired every 25 μm below the brain surface at 15 min. The scale bar in (panel g) is 50 μm. Panels a-g are at the same magnification. The vasculature was identified by intravenously injected Texas Red-dextran (70 kDa)