Fig. 7.

The effects of application and removal of nicardipine (Nc) on SV2 and opsin synthesis in photoreceptors as measured with colocalization analysis. Area is derived from the number of pixels labeled by rab6 and either SV2 or opsin antibodies. A, SV2 and rab6 labeling in cone and rod cells from 3-d-old cultures that had been treated with Nc after 1 d in culture. In rod cells, the Nc treatment significantly reduced the SV2 labeling in the Golgi, resulting in a smaller average area of colocalized staining. There was no change in cone cells. A total of 120 cells in six cultures from three animals were analyzed.B, SV2 and rab6 labeling in cone and rod cells from 6-d-old cultures; Nc had been removed at day 3 (Fig. 1). The SV2 staining increased significantly in Nc-treated rod cells after Nc removal, increasing the areas of colocalization (**p < 0.01), but showed no significant change in Nc-treated cone cells. A total of 80 cells in four cultures from one animal were analyzed. C, Rod opsin (4D2) and rab6 labeling in rod cells from 3-d-old cultures. No change in the area of double labeling was observed in Nc-treated rod cells compared with untreated cells, suggesting that Nc had no effect on opsin synthesis. A total of 40 cells in four cultures from two animals were analyzed.