Fig. 5

CaM knock-down induces an activity-dependent reduction in olfactory sensitivity. a, b CaM knock-down after OR expression has begun using Orco-GAL4 does not affect the sensitivity of ab2A neurons to methyl acetate (a) and slightly reduces the sensitivity of ab3A neurons to ethyl butyrate (b). c When we maintained the same flies in vials containing 10 % ethyl acetate, which activates ab2A, we found CaM knock-down produces a dramatic reduction in the sensitivity of ab2A neurons to methyl acetate. d When we maintained these flies in vials containing 10 % ethyl butyrate, we observed a similar but even more significant reduction in the sensitivity of ab3A to ethyl butyrate. e, f This effect of CaM-IR is OSN subtype-specific, as long-term exposure to 10 % methyl hexanoate—a ligand for ab3A but not ab2A—does not affect ab2A sensitivity (e) but strongly reduces ab3A sensitivity (f). For all graphs, data are presented as means ±95 % confidence intervals. n ≥ 8 sensilla for each genotype and odorant dose. Asterisks indicate significant differences between the experimental line and both controls, with the higher of the two P values determining the number of asterisks (two-way ANOVA; Bonferroni post-hoc test; * P < 0.05, ** P < 0.01, and *** P < 0.001). We used the following precise genotypes: [UAS-Dcr-2/UAS-CaM-IR (II); Orco-GAL4 (III)], [UAS-Dcr-2/+ (II); Orco-GAL4 (III)], and [UAS-CaM-IR/+ (II)]. CaM calmodulin, ns non-significant, OSN olfactory sensory neuron, OR odorant receptor