English: TIRF-Microscopy (top) and membrane capacitance (bottom) recording of the cell shown in Figure 1a. This cell was stimulated for 2 s by depolarizing pulses and is shown 4 s prior to and 8.5 s after stimulation. Secretion of vesicles seen as a sharp decrease of fluorescence of individual spots (highlighted by white arrows) occurs simultaneously to the increase in membrane capacitance and only during the stimulation period (marked in red). Before and after stimulation vesicles may enter or leave the evanescent field as can be seen by a slow increase or decrease of individual fluorescent spots. Acquisition and display rate are 5 Hz.