Figure 6. Exocytosis in β-cell elicited by action potential-like stimulation.

A, a β-cell was stimulated by a train of 50-ms depolarizations from −70 mV to 0 mV applied at a frequency of 4 Hz (top). Exocytosis was measured as a capacitance increases (ΔC, bottom). Data represent the average of 16 separate experiments. The continuous superimposed curve was derived by low-pass filtering the capacitance signal at 100 Hz and using the function of sigmoidal Weibull function (type-2). B, time derivative (δC/δt) of the continuous curve in A.