Figure 9.

Total postsynaptic metabotropic glutamate receptor area within cone pedicles is increased in the mutant retina. (a) Co-labeling of cone pedicles (cone-arrestin) and metabotropic glutamate receptor 6 (mGluR6) on ON bipolar cell dendritic tips at P11. Insets show higher magnification images of the cone pedicles and mGluR6 receptor clusters (arrows). mGluR6 immunoreactivity outside the cone pedicles is associated with rod photoreceptor terminals. (b) Within each cone pedicle, a threshold was applied to the mGluR6 signal and the total area of pixels with intensities above the threshold is plotted against pedicle area. (c) For each cone, the total pixel area corresponding to mGluR6 signal above threshold is presented as a percentage of the area of that cone pedicle. n = number of pedicles analyzed, two animals each for control (three fields) and mutant retinas (three fields).