Fig. 3
From: The sigma-1 receptor modulates methamphetamine dysregulation of dopamine neurotransmission
σ1R activation decreases METH-stimulated dopamine efflux without affecting uptake. a Schematic of the setup is shown. YFP-DAT cells loaded with dopamine were voltage clamped while oxidative currents were measured via an amperometric electrode. Dopamine is represented in purple and DAT in pink. Cell, molecules, and proteins images are courtesy of Servier Medical Art, licensed under CC BY 3.0 (https://creativecommons.org/licenses/by/3.0/legalcode). b Representative traces show METH-stimulated (10 µM) dopamine efflux after 30-min treatment with vehicle, 1 µM PRE-084, or 1 µM BD1063 plus 1 µM PRE-084. METH increased dopamine efflux (top panel), while PRE-084 significantly decreased the effect of METH (middle panel). BD1063 blunted the effect of PRE-084. c Bar graph shows the average METH-stimulated dopamine efflux above baseline following treatment with vehicle, PRE-084, or BD-1063 + PRE-084 (n = 4, 4, and 6 cells, respectively, F (2,11) = 15.18, P = 0.0007, one way ANOVA; Tukey’s test for multiple comparisons, *P < 0.05 and *** P < 0.001). d [3H]DA uptake was measured in FLAG-DAT cells. 10 μM METH (15 min) significantly decreased [3H]DA uptake compared to vehicle. 30-min PRE-084 treatment had no effect on basal uptake or METH-inhibition of uptake. Data is represented as percent vehicle control (n = 3 independent experiments; F (1,20) = 90.34, P = 0.0009, two-way ANOVA for Vehicle × METH; F (4,20) = 1.363, P = 0.2821, two-way ANOVA for PRE-084 treatment; Bonferroni’s test for multiple comparisons of Vehicle vs. METH, **P < 0.01 and ***P < 0.001). e ASP+ uptake was measured in YFP-DAT cells, shown in left panels (scale bar: 10 μm). f Line graph shows average fold ASP+ fluorescence increase over time. METH (n = 11) significantly decreased ASP+ uptake compared to vehicle (n = 14), while PRE-084 treatment did not affect baseline (n = 9) or METH-inhibition of uptake (n = 8) (n represents independent experiments; F (3,63) = 156.8, P < 0.0001, two-way ANOVA for Time; F (9,117) = 4.959, P = 0.0480, two-way ANOVA for Treatment; Bonferroni’s test for multiple comparisons, *P < 0.05 for METH groups vs. non-METH groups at 300 s). Data is represented as mean ± SEM
