Figure 2.

Expression of GFP in neurons after intranasal infusion of AAV9-GFP. Tissue sections from MPS I mice intranasally administered AAV9-GFP vector were co-stained for GFP and for olfactory marker protein (OMP), which is expressed exclusively in the olfactory bulb in the brain (described in Materials and Methods). Higher magnification images demonstrate that GFP-ir (green; A and E) and OMP-ir (red; B and F) are distinctly co-localized in glomeruli of the olfactory bulb (yellow; C and G), demonstrating AAV9-GFP transduction in OMP-positive neurons. Due to the high intensity of GFP staining, the green and red images were thresholded separately, and images were merged (using the Photoshop function “multiply”). The overlapping pixels where co-localization is present are shown in white (D and H). Scale bars A–D = 100 μm, E–H = 50 μm.