Figure 7. Axial mobility of secreted vesicles was reduced to a minimum immediately before fusion.

(A) Histogram of the averaged axial CD distribution of secreted vesicles from cells at a pre-stimulus [Ca²⁺]_i of 590 nM (black). Data points are represented by circles, and the solid line represents the log-normal fit. The CD values were calculated from the last 15 s prior to fusion induced by a train of depolarizations. The two fits obtained from resting cells kept at 100 nM (blue) and 500 nM (red) [Ca²⁺]_i were plotted for comparison. N_100nM/n: 23/719; N_500nM/n: 26/695; N_secreted/n: 19/53. Note the large left shift of the histogram of axial CDs measured from secreted LDCVs compared to the histograms of cells at rest. (B) Mobility of LDCVs during the last second prior to secretion. The stimulation protocol is shown on top.