Figure 1. Exocytosis during repetitive stimulation is strongly inhibited in bovine adrenal chromaffin cells expressing Rab3AQ81L.

A, capacitance (C_m) and first and last inward currents (I_Na,_Ca) recorded during stimulation with a train of 10 ms depolarizations (30 pulses, −90 mV to +20 mV, 200 ms interval between pulses) in four different bovine chromaffin cells infected with control adenovirus (GFP–IRES–β-galactosidase). Bars under the C_m traces indicate timing of depolarizations. Dashed lines indicate initial C_m or holding current. B,C_m and I_Na,Ca recorded during stimulation with a train of 10 ms depolarizations in four different bovine chromaffin cells infected with Rab3AQ81L adenovirus (Rab3AQ81L–IRES–GFP). C, average C_m response (ΔC_m) for each pulse of the train in control and Rab3AQ81L-expressing cells. D, average calcium influx (calculated from integral of calcium current) for each pulse of the train. n= 9 and 10 cells for control and Rab3AQ81L, respectively. [Ca²⁺]_o= 5 mmol l⁻¹. Error bars are ±s.e.m.