Figure 4. Role of IP3 signalling in inspiratory bursts.
A, nystatin perforated-patch recordings served as control. The IP3R antagonist xestospongin (Xes; 1 μm), applied intracellularly by patch rupture, reduces inspiratory bursts. Subsequent bath application of LY367385 (LY; 15 μm) additionally attenuates inspiratory bursts. B, same protocol as A, except that MPEP, and not LY, is bath applied in steady-state Xes conditions. MPEP has no additional effects on inspiratory bursts. Baseline membrane potential was −60 mV. A and B have separate calibration bars as shown.