(A–B) Single-sensillum recording from the at4A ORNs that express Or47b. Palmitoleic acid-evoked spike responses in 2-day old (A) and 7-day old (B) males. Corresponding spike rasters (middle) and peri-stimulus time histogram (bottom, binned at 50 ms) are shown below the sample traces (n=21). (C–D) Palmitoleic acid-evoked calcium response at the Or47b axon terminals in 2-day old (C) and 7-day old (D) males. Dose-response curves comparing Or47b ORN spike responses (E) or calcium responses at ORN axonal terminals (F) between 2-day and 7-day old males (*, p<0.05; **, p<0.01; ***, p<0.001, t-test). (G) As in (F), imaging from female flies. Mean± s.e.m. (n=7–9 for imaging). Dose response comparisons between 2-day and 7-day old flies are from parallel experiments (palmitoleic acid: 4.5 ng to 450 μg).