Fig. 4

Amphetamine-induced efflux via OCT3. a Cartoon depicting experimental paradigm used for panels b–f. Under control conditions, microsuperfused ASP⁺ accumulates in YFPhOCT3 HEK293 cells leading to an increase in relative fluorescent units (RFUs) with time. Inhibitors of OCT3 block this accumulation. b Uptake of ASP⁺ in YFPhOCT3-expressing cells and parental HEK293 cells. Data are shown as mean ± S.E.M., n = 6–10 recordings per cell line. c Addition of MPP⁺ concentration-dependently inhibited uptake of ASP⁺ (arrows indicate the addition of ASP⁺ and MPP⁺). Shown are representative traces for each condition. For analysis, the area under the curve was calculated for each trace after the first 60 s. *P < 0.05, Kruskal–Wallis, followed by Dunn’s (d). e No detectable difference in ASP⁺ uptake upon addition of AMPH (40 µM) and cocaine (COC, 100 µM). Corticosterone (CORT, 10 µM) fully inhibited ASP⁺ uptake. Addition of ASP⁺ and the substance of interest (S.O.I.) is indicated by arrows. Shown are representative traces for each condition. For analysis, the area under the curve was calculated for each trace after the first 60 s. *P < 0.05, Kruskal–Wallis, followed by Dunn’s (f). g AMPH-induced efflux of pre-loaded [³H]MPP⁺ from YFPhOCT3 cells transiently transfected with hVMAT2 vs. vehicle-treated control. Addition of AMPH at t = 0 min is indicated by the black bar; Data are mean ± S.E.M., n = 9–12 independent observations, * indicates difference vs. control (*P < 0.05, Bonferroni’s)