Number of vesicles residing at the plasma membrane between 0.5 and 5 s was reduced at an [Ca²⁺]_i of 500 nM compared to 100 nM.

<p>(<b>A</b>) Density of labeled LDCVs at the footprint of the cell per frame. (<b>B</b>) Sum of labeled LDCVs visualized over the whole recording period (2 min) normalized to the footprint area of the cell. A gradual reduction can be observed by increasing the free [Ca²⁺]_i above 200 nM. (<b>C</b>) Logarithmic plot of vesicles vs. residence time. Data were normalized to the footprint area and the total count of vesicles per cell (TCV) over 2 min (blue: 100 nM [Ca²⁺]_i; red: 500 nM [Ca²⁺]_i). (<b>D</b>) Averaged distribution of residence times of LDCVs in the evanescent wave at all [Ca²⁺]_i. Data were normalized to the footprint area and the TCV over 2 min. N_100nM/n: 23/832; N_300nM/n: 13/514; N_500nM/n: 26/958; N_700nM/n: 14/359; N_{>800 nM}/n: 16/512; *<i>P</i><0.05; **<i>P</i><0.01.