Figure 4. Metitepine is an antagonist of all known Drosophila 5-HT receptors.

(a) Traces show calcium responses for each receptor to increasing concentration of 5-HT (red arrow: μM; orange arrow: nM). All traces are average responses in black (± s.e.m. in gray) of 10–12 simultaneously recorded cells. (b) Dose-response curves were obtained normalizing the peak response at each concentration of 5-HT to the maximal response in that cell (ΔF/ΔF_MAX). n = 3–6 plates, 10–12 cells each. (c) Traces of cells after treatment with serotonin and then solvent. (d) Traces of cells after treatment with serotonin and then 100 μM metitepine. (e) Inhibitory dose-response curves of metitepine. In b and e, error bars are s.e.m.