Figure 3.

Selective reduction of pre- and post-synaptic protein expression in Nfasc CKO (A–D). Pre-synaptic Bassoon (magenta) and post-synaptic mGluR6 (green) protein is significantly reduced in Nfasc CKO compared to controls (A). Insets are zoomed images of dotted boxed region. At P30, Bsn and mGluR6 forms a puncta-like structure with 0.6 and 1.0 μm in size, respectively. Number of Bsn and mGluR6 puncta were counted in the OPL with an area of ~2,500 μm². A total of 10 different confocal sections were analyzed from four control animals (n = 40) and four Nfasc CKO animals (n = 40). Data are represented as mean values ± SEM. Statistical significance was determined using an unpaired t-test. *p < 0.0001. Images are shown as a single confocal section. Scale bar, 10 μm (A). Rod terminals appear to be normally positioned in the OPL in Nfasc CKO (B). Staining with anti-PSD-95 (magenta) and anti-CtBP2 (magenta) shows expression is not affected even in areas where mGluR6 expression is reduced (green, white). Cone terminals appear to be unaffected as denoted by white and yellow arrows (B). Dendrites of rod bipolars (anti-PKC, green) and cone bipolars (anti-Scgn, green) are localized to the OPL in both Nfasc CKO and control retinas. Bsn puncta (magenta, green) appears to be reduced in the rod synaptic layer as outlined by black brackets and not in the cone synaptic layer as seen with anti-CAR (magenta) and depicted with white arrows (C). Quantification of CtBP2 puncta within the OPL shows no statistical difference between Nfasc CKO and controls. The average number of Bsn puncta per cone terminal within a confocal section are plotted. These measurements were taken from 12 different retinal sections from four control and four Nfasc CKO mice. A total of 118 cone terminals were analyzed for controls and 101 for Nfasc CKO (D).