Fig. 8. Effects of injection. Response of pyrrolizidine alkaloid (PA) cells in the lateral galeal sensillum to 10^-7 mol l^-1 seneciphylline N-oxide after injection of saline or 5 µl of 1% monocrotaline. Data for the saline-injected individuals (N=9) are shown as means ± S.E.M. (broken line). Data for injected insects (N=10) are shown as individual trajectories. The arrow indicates injection time (within 10 min of the initial recording).