Figure 1.

Olfactory neuron response to high concentrations of ammonia

(A) Representative traces (top) and mean responses (bottom) for a 1-s period of stimulation from each sensillum in response to ammonia. The 1-s stimulation period is indicated by the black bar above each trace. Counting for the responses marked “1.2s–2.2s” was begun at the start of the increase in spike frequency (∼1.2 s mark on the recording). Counting for the responses marked “9s–10s” was measured during the last second (from 9s to 10s) on each recording. All recordings were obtained from 3–5 day old wildtype (CS) flies. n = 5–13 sensilla from 6 flies. Error bars indicate SEM Dots indicate responses from individual sensillum. For each sensilla type repeated measures 1-way ANOVA with Geisser-Greenhouse correction was followed by Tukey’s test for multiple comparisons. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001; ∗∗∗∗p < 0.0001.

(B) Representative traces (top) and mean responses (bottom) of the ab2 sensillar neurons to a 1-s stimulus of indicated concentration of ammonia. The 1-s stimulation period is indicated by the black bar above each trace. Counting for the responses marked “1.2s–2.2s” was begun at the start of the increase in spike frequency (∼1.2 s mark on the recording). Counting for the responses marked “9s–10s” was measured during the last second (from 9s to 10s) on each recording. All recordings were obtained from 3–5 day old wildtype (CS) flies. n = 6–14 sensilla from 6 flies. Error bars indicate SEM Dots indicate individual data points. Repeated measures mixed-model test with Geisser-Greenhouse correction followed by Tukey’s test for multiple comparisons. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001; ∗∗∗∗p < 0.0001.

(C) Representative traces (left) and mean responses (right) for the ab2 sensilla to headspace of 1% solutions of known stimulating odorants (10⁻²). The 1-s stimulation period is indicated by the black bar above each trace. “Pre-NH₃” denotes that the recording precedes exposure, while “Post-NH₃” denotes that the recording follows a 1-s exposure to 3% ammonia. All recordings were obtained from 3–5 day old wildtype (CS) flies. n = 5–6 sensilla from 6 flies. Error bars indicate SEM Dots indicate individual data points. Repeated measures 1-way ANOVA with Geisser-Greenhouse correction followed by Tukey’s test for multiple comparisons. ∗p < 0.05; ∗∗p < 0.01.

(D) Representative traces (left) and mean receptor potential responses (right) to 1% solutions of indicated odorants (10⁻²) in the ab2 sensillum both pre and post exposure to 3% ammonia. All recordings were obtained from 3–5 day old wildtype (CS) flies. n = 6 sensilla from 6 flies. Error bars indicate SEM Dots indicate individual data points. Repeated measures 1-way ANOVA with Geisser-Greenhouse correction followed by Tukey’s test for multiple comparisons. ∗p < 0.05; ∗∗p < 0.01.