Figure 5. Effect of octopaminergic agonist and antagonist on olfactory responses using single sensillum recordings.

(A) Injection of clonidine, an octopamine receptor agonist, into the antennae resulted in a drastic decrease in the number of spikes right after injection until the end of the experiment (Phase II and III), compared with “before injection” (Phase I) (N=5, p<0.001). (B) Injection of the octopamine receptor antagonist, yohimbine, induced a slight increase in the middle of time phase (II-b, 6^th~9^th pulses), compared with “before injection” (N=5, p<0.001). One-way ANOVA test followed by Bonferroni correction for multiple comparisons was employed for statistical analysis.