Fig. 10. Effect of ryanodine (10 µmol l^-1) on the [Ca²⁺]_i and force responses of an OOM to two concentrations of proctolin (10 nmol l^-1 and 1 µmol l^-1). The OOM had been superfused with saline-containing ryanodine for a minimum of 30 min before the peptide challenges. Stimulus trains consisted of 1 ms pulses, 50 Hz, 500 ms train duration, 0.1 trains s^-1.