Skip to main content
. Author manuscript; available in PMC: 2017 Nov 30.
Published in final edited form as: Mol Psychiatry. 2017 Feb 14;22(12):1735–1745. doi: 10.1038/mp.2017.9

Figure 1.

Figure 1

Pharmacological inhibition and activation of VTA Cav1.3 channels oppositely regulates cocaine behaviors. (a) Western blot showing the presence of Cav1.3 protein in VTA PSD fractions from wildtype (WT) and Cav1.3 knockout (KO) mice. (b) Schematic of Cav1.3 showing its ITTL in the C-terminal cytoplasmic domain and its interaction with PSD-95 and Shank. (c) Western blots showing immunoprecipitated PSD95 and Shank with Cav1.3 antibody in VTA protein lysates. (d) Disruption of Cav1.3 PDZ domain ITTL with an inhibitory peptide blocks KCl- (Two-way ANOVA, [Peptide x KCl, F(1, 20) = 4.831, P=0.0399]; Bonferroni post hoc, Control Peptide: Vehicle vs KCl *P<0.05, KCl: Control Peptide vs ITTL Peptide †P<0.05) and BayK- (Two-way ANOVA, [Peptide x BayK, F(1, 20) = 7.593, P=0.0122]; Bonferroni post hoc test: Control Peptide: Vehicle vs BayK *P<0.05, BayK: Control Peptide vs ITTL Peptide ††P<0.01) induced Ser 133 P-CREB phosphorylation in VTA slices from Cav1.2 DHP−/− mice. For all groups, n = 6. (e, f, i, l) Schematic timeline of behavioral protocol and VTA infusion of either Veh or Nif, Veh or BayK in Cav1.2DHP−/− mice, or Cav1.3 shRNA in C57BL/6 mice. (g-h) Intra-VTA microinjection of Nif in Cav1.2 DHP−/− mice administered prior to each cocaine conditioning session attenuated (g) expression of CPP on Day 5 (WD1) and Day 34 (WD30) (Two-way ANOVA, [VTA infusion x day, F(2,60) = 7.595, P=0.0011]; Bonferroni post hoc test: Veh: Day 1 vs Day 5 ***P<0.001, Veh: Day 1 vs Day 34 ***P<0.001, Day 5: Veh vs Nif ††P<0.01, Day 34: Veh vs Nif †††P<0.001. Veh n = 12, Nif n = 10), and (h) the cocaine-induced locomotor activity measured on day 36 (t(17) = 2.86, *P=0.0108. Veh n = 10, Nif n = 9). (i) Inset, image shows green fluorescent protein (GFP-green), tyrosine hydroxylase (TH-red) and dual-labeled (yellow) cells. (j, k) Intra-VTA stereotaxic delivery of Cav1.3 shRNA (21 days before the start of CPP) attenuated (j) the expression of CPP tested on day 5 and 34 (Two-Way ANOVA, [VTA injection x day, F(2,51) = 14.09, P< 0.0011]; Bonferroni post hoc test: Ctrl shRNA: Day 1 vs Day 5 ***P<0.001, Ctrl shRNA Day 1 vs Day 34 ***P<0.001, Day 5: Ctrl shRNA vs Cav1.3 shRNA ††P<0.01, Day 34: Ctrl shRNA vs Cav1.3 shRNA †††P<0.001. Ctrl shRNA n= 10, Cav1.3 shRNA n = 9), and (k) cocaine-induced locomotor activity measured on day 36 (t-test, t(17) = 3.066, **P=0.0070. Ctrl shRNA n = 10, Cav1.3 shRNA n = 9). (m, n) Intra-VTA infusion of BayK prior to each cocaine conditioning session enhanced (m) expression of cocaine CPP on day 5 and 34 (Two-way ANOVA, [VTA infusion x day F(2,48) = 3.206, P=0.0493]; Bonferroni post hoc test: Veh: Day 1 vs Day 5 ***P<0.001, Veh: Day 1 vs Day 34 **P<0.01, Day 5: Veh vs BayK †P<0.05, Day 34: Veh vs BayK †P<0.05. Veh n = 9, BayK n = 9), and (n) enhanced cocaine-induced locomotor response on day 36 (t(16) = 3.955, **P=0.0011. Veh n = 9, BayK n = 9). Error bars represent ± s.e.m.