Figure 8
From: Assembly of the outer retina in the absence of GABA synthesis in horizontal cells
Ribbons are present and localized to synaptic sites in the mutant retina. (a) Immunostaining for cone pedicles (cone-arrestin) and ribbons (C-terminus binding protein 2 (CtBP2)) in littermate controls and knockout regions of the mutant retina. Insets show higher magnification of cone pedicles marked by arrows in merged images. Arrows in insets indicate bright CtBP2 immunoreactivity - note more rounded structures at P11 compared to ribbon-like structures at P21 for cones. C, cone ribbons. Additionally, higher magnifications of CtBP2 immunostained horseshoe-like ribbons in rod terminals (R) are shown for the P21 retinas. (b) Examples of the ultrastructure of a cone and rod pedicles in control and mutant retinas showing localization of ribbons at synaptic triads. For each of the cone examples, the asterisk indicates the same triad shown in the left and middle columns (h, horizontal cell process; b, bipolar cell dendrite).