IR-expressing OSN response polarity and pulse resolution. (A) Mean normalized PSTH response of Ir41a-expressing OSNs to repeated pulses of log [−2] v/v 1, 4-diaminobutane at listed frequencies. Traces below each panel show sample 50 ms recordings. Square pulses indicate stimulus presentation. (B) As in (A) for log [−2] v/v of the inhibitory odor isoamyl amine. Red line indicates baseline frequency. (C) Mean normalized PSTH response of Ir41a-expressing OSNs to a binary mixture of 1, 4-diaminobutane and isoamyl amine at [−2] v/v. (D) Mean percent return to base line to the excitatory ligand across all pulses at listed frequencies, error bars indicate SEM (ANOVA, P < 0.05, followed by Tukey post-hoc test, n = 7–8) (E), as in (D) for log [−2] v/v of the inhibitory odor isoamyl amine (ANOVA, P < 0.05, followed by Tukey post-hoc test; n = 7–9). (F) as in (D) for the binary mixture (ANOVA, P < 0.05, followed by Tukey post-hoc test, n = 7–9).