IR56d neurons are selectively responsive to short and medium-chain FAs.
(A) PER in response to short-chain pentanoic acid (PeA, n = 46), medium-chain octanoic acid (OcA, n = 26), and long-chain oleic acid (n = 46) in TNT and control impTNT flies. Blocking synaptic release in IR56d neurons with TNT significantly decreases PER to octanoic acid (n = 29), but does not affect PER for pentanoic (n = 42) or oleic acid (n = 42). Wilcoxon Rank-Sum Test; ***p<0.001. (B) Average peak %ΔF/F for the posterior projections of IR56d neurons in response to water, 1% DMSO, pentanoic acid, octanoic acid, and oleic acid (n = 9, 8, 9, 9, 8, respectively), and (C) the anterior projections (n = 9, 7, 9, 9, 7, respectively). Error bars indicate SEM. One-way ANOVA with Tukey’s HSD; ***p<0.001.