(A) Structures of 4Br-NAL-phe, 4F-NAL-phe, and 3,4,5F-NAL-phe. (B) Representative traces for 4Br-NAL-phe (pink), 4F-NAL-phe (teal), and 3,4,5F-NAL-phe (purple) with 0 μM PUFA (left) and 20 μM PUFA (right). (C, E, G) I/I0, (E) ΔV0.5, and (G) Gmax dose–response curves for NAL-phe (n = 4), 4Br-NAL-phe (n = 3), 4F-NAL-phe (n = 4), and 3,4,5F-NAL-phe (n = 5) with dotted line representing dose response of NALT (n = 4). (D, F, H) Maximum effects on (D) I/I0, (F) ΔV0.5, and (H) Gmax (at 20 μM) for 4Br-NAL-phe (n = 3), 4F-NAL-phe (n = 4), and 3,4,5F-NAL-phe (n = 5). Asterisks indicate statistically significant differences determined by one-way ANOVA with Tukey’s test for multiple comparisons. Values for all compounds and concentrations available in Figure 3—source data 1.