Fig. 5. Effect of Q/E mutations of the kinetics of single granule release events. Data was taken from chromaffin cells following transfection. Non-transfected cells in the same dishes were used as controls for comparison with cells expressing Em2 or the double Q/E mutations. Identified spikes were analysed using Origin and the rise time to peak determined for each spike. (A) Values of rise time shown as mean±s.e.m. (B-D) Frequency distribution of rise-times for control (n=727 spikes), Em2 expressing (n=440 spikes) and double-mutant expressing (n=343 spikes) cells.