Figure 8. Absence of C-terminal-binding protein 1(CtBP1) does not affect FM4–64 destaining evoked by depolarization in bipolar-cell synaptic terminals. A: The graphs show examples of destaining elicited by activation of calcium current for 500 ms (arrow) in a wild-type (WT) and CtBP1-knockout (KO) bipolar-cell terminal, preloaded with FM4–64. Each data point shows the average fluorescence of the terminal for each image in a series of ten confocal images before and ten images after depolarization. The horizontal lines indicate the average fluorescence for each series. Fluorescence is normalized with respect to the maximum. An arbitrary break was introduced in the abscissa for visual clarity. B: The graph shows the average percentage loss of FM4–64 fluorescence elicited by 500-ms depolarization to activate calcium current and trigger synaptic vesicle fusion in WT (n=14 cells in three animals) or KO (n=15 cells in three animals) bipolar cells. The error bars show ±one standard error of the mean. The difference is not statistically significant (p=0.30).