Fig. 8. (A,B) Neither of the two action potential (AP) classes was significantly influenced by amine injections. The frequencies of small and large action potentials were evaluated for segments 10 min in duration within 30 min before (_before) and after (_after) drug injections, and the normalized frequency _after/_before was computed. For comparison, data segments of 10 min, separated by 40-50 min, but without any injection, were analyzed the same way. One-way analysis of variance (ANOVA) did not reveal significant differences between any dose of the injected drugs, the control (injected with haemolymph Ringer) and the non-injected state. Values are medians + S.E.M. Values of N given in A also apply to B. 5-HT, serotonin; OA, octopamine; HLR, haemolymph Ringer.