Fig. 1. In vitro assays.

a 5-HT2AR-mediated calcium mobilization assay of the tested 5-MeO-tryptamines and reference compounds 5-HT (full agonist) and dopamine (DA; partial agonist). Data are expressed as means ± SD for N ≥ 3 experiments. b 5-HT uptake inhibition at SERT. Data are expressed as percentage of control uptake (absence of tryptamine), as means ± SD for N ≥ 3 experiments. c–f Effects of 5-MeO-DMT, 5-MeO-MET, 5-MeO-DET and 5-MeO-pyr-T on transport-mediated batch release of preloaded [³H]5-HT from HEK293 cells stably expressing SERT. *p < 0.05, **p < 0.01, ***p < 0.001 vs release in absence of monensin (mixed-effects model, employing Šidák’s correction; N = 5). g–j Whole-cell patch clamp experiments used to identify tryptamine-induced SERT-mediated inwardly directed currents in HEK293 cells (N = 5). k–n Representative single-cell traces showing currents elicited by 10 µM of 5-MeO-DMT, 5-MeO-MET, 5-MeO-DET, and 5-MeO-pyr-T. Data are presented as means ± SD for N = 5 independent experiments. o Concentration-response relationship of 5-MeO-pyr-T measured in superfusion release assays at different concentrations, as percentage of total efflux (N = 5). KHB and pCA were used as control substances. *p < 0.05, **p < 0.01, ***p < 0.001 versus KHB, ^###p < 0.001 vs pCA (Tukey’s test).