Figure 5.

Bar graphs illustrating the transient effect of flying on aggression (A) compared with octopamine and the octopamine agonist CDM (B) and amine depletion (C). Pairs of crickets were first treated as indicated by the key on the left and were then matched (initial fight). The same pairs were then rematched: <3 min after the initial fight (loser test) and 15, 30, and 45 min later (reengagement 1, 2, and 3; each preceded by a loser test). Circles, Median level of aggression; bars, i.q.r. A, White bars, untreated (n = 24 pairs); hatched bars, flown for 0.5 min (n = 15 pairs), 1.5 min (n = 19 pairs), and 3 min (n = 43 pairs). B, Light gray bars, Ringer injected 20 min previously (n = 53 pairs); dark gray bars, octopamine injected (50 μl; 100 mm; n = 20 pairs); black bars, CDM injected (100 μl; 2 mm; n = 50 pairs); black stippled bars, CDM treated (∼12 h later; n = 14). C, lightly stippled bars, AMTP treated (i.e., serotonin-depleted) (n = 27 pairs; 1 mg of AMTP each 2, 4, and 6 d before testing); darkly stippled bars, AMT treated (n = 15 pairs; 1.5 mg of AMT each 2 and 4 d before testing); hatched bars, AMT treated and flown for 3 min before the initial fight (n = 45); black bars, AMT treated and injected with 100 μl of 2 mm CDM 20 min before the initial fight (n = 10 pairs). Asterisks denote statistically significant differences of test groups compared with nontreated crickets in A and compared with Ringer-treated crickets in B and C (Mann-Whitney U test; ^*p < 0.05; ^**p < 0.01; ^***p < 0.001).