Fig. 10
From: The sigma-1 receptor modulates methamphetamine dysregulation of dopamine neurotransmission
σ1R activation significantly decreases METH-induced increases in intracellular calcium. a Representative images of YFP-DAT cells (left panel) treated with Fura-2AM before and after treatment with 10 μM METH. Middle and right panel show the ratio 340/380 view. Scale bar is 5 μm. The color bar in the Fura-2 images represent the color assignments for the 340/380 ratio of the cells. b PRE-084 did not change calcium levels compared to vehicle treatment. Bar graph shows the average calcium responses after acute vehicle (n = 3) or 1 μM PRE-084 treatment (n = 3, n represents independent experiments including 19–20 cells; t = 0.699, P = 0.5159, unpaired t-test). c PRE-084 treatment significantly decreased METH-stimulated intracellular calcium increase compared to vehicle-treated cells. Bar graph shows METH-mediated calcium response over baseline in vehicle treated (n = 8) and 1 μM PRE-084 pretreated (30 min) cells (n = 8). METH did not increase intracellular calcium in parental cells not expressing DAT (n = 5) (n represents independent experiments; F (2,18) = 3.4, P = 0.0001, one-way ANOVA, Tukey’s test for multiple comparisons). d Grayscale images of vehicle (top panel) or PRE-084 (bottom panel) pretreated neurons expressing the calcium indicator GCaMP6f before and after treatment with 10 μM METH. Scale bar is 20 μm. e PRE-084 does not change baseline calcium levels in dopamine neurons. Bar graph shows the average calcium responses after acute vehicle (n = 19) or 1 μM PRE-084 treatment (n = 11) (n represents neurons; t = 0.699, P = 0.5159, unpaired t-test). f METH increase intracellular calcium in the dopamine neurons, and this effect is blocked by pretreatment with nomifensine. PRE-084 treatment significantly decreases METH-stimulated intracellular calcium increase compared to vehicle-treated neurons. The effect of PRE-084 was blocked by pretreatment with BD-1063. Bar graph shows METH-mediated calcium response over baseline in vehicle treated (n = 53) and 1 μM PRE-084 pretreated (30 min) neurons (n = 42). (n neurons; F (3, 113) = 3.662, P = 0.0001, one-way ANOVA, Dunnett’s test for multiple comparisons.) Data is represented as mean ± SEM
