Figure 7.

Spontaneously recycling SVs were included in the total recycling pool. A, Diagram represents the timeline of the sequential labeling experiment. Spontaneous SV labeling in TTX for 120 min was performed after (post-HK) or before (pre-HK) the evoked SV labeling in 5 min HK depolarization. Fish preparations were subjected to incubation with HL-Cy5 (magenta square) followed by HK depolarization (boxed in orange) or to incubation in the presence of TTX (boxed in blue). B, SV fraction labeled with HK only (control) or sequentially with both HK and TTX (+spontaneous) in post-HK labeling (n = 12 or 11 fish, respectively) and pre-HK labeling (n = 12 or 12 fish, respectively). No significant difference was observed between the two groups both in post-HK (p = 0.67, unpaired t test) and pre-HK (p = 0.90, unpaired t test) labeling. C, Average cumulative probability of F_Cy5/F_{pH (pH7.4)} at individual ROIs from the data analyzed in B. No significant difference was observed between the two groups in both post-HK (p = 0.44, Kolmogorov–Smirnov test) and pre-HK (p = 0.32, Kolmogorov–Smirnov test).