Identification of new Orco antagonists.

A) Co-application of 100 µM OLC2 inhibits activation of Dmel\Orco by 30 µM OLC12. B) Co-application of 100 µM OLC8 fails to block activation of Dmel\Orco by 30 µM OLC12. C–D) Results of a screen of 20 compounds for Orco antagonism. Responses of Dmel\Orco + Dmel\Or35a to 10 µM OLC12 (EC₂₅) (C) or of Dmel\Orco to 30 µM OLC12 (EC₃₉) (D) in the presence of 100 µM of each candidate antagonist are presented as a percentage of the average of the two preceding responses to OLC12 alone (mean±SEM, n = 3−6). Sh, sham. E) Structures of Orco antagonists.