Figure 4
Mating decreases DA1 activity and requires Or65a OSNs to suppress cVA attraction.
(A and B) Or67d OSN response to different amounts of cVA. (A) Spike trains in response to cVA (red bar shows stimulus duration) recorded from unmated females and (B) comparison between virgin and mated females (n = 10 for each). (C and D) Calcium imaging during cVA application in the DA1 glomerulus at the presynaptic (OSNs) and postsynaptic (PNs) level. (C) Representative false color-coded images showing the antennal lobe after stimulation with cVA in OSNs and PNs in unmated females. (D) Comparison of DA1 calcium activity in virgin (ORNs, n = 6; PNs, n = 9) and mated (ORNs, n = 7; PNs, n = 5) females elicited by cVA. Asterisks show significant differences between virgin and mated females (GLMM). (E) Effect of blocking Or65a OSN response on cVA attraction of mated females (n = 20 to 28). Tetanus toxin light chain (TeTxLC) was expressed in Or65a OSNs, using two independent lines (TeTxLC tnt1 and TeTxLC tnt2). As a negative control an inactive form of TeTxLC was expressed (TeTxLC (−)1 and TeTcLC (−)2). Asterisks above bars indicate significant attraction (Wilcoxon test, * p < 0.05, ** p < 0.01). Data are mean ± SEM. (F) Proposed mechanism underlying the suppression of cVA attraction in females after mating. During mating, females are exposed to high amounts of cVA, which activates Or65a neurons. Or65a OSNs decrease the activity of DA1 glomerulus, probably via LNs. Decreased DA1 activity results in an inhibition of cVA attraction. Photo by S. Lebreton.
