Fig. 2: Enhanced GABAergic tone from the RMTg during conditioning to cocaine attenuates changes in ERK, PERK, and GluA1ps845 in the VTA.
All rats were euthanized 45 min after the RePP test. Then, their VTA was taken out and homogenized. Samples were resolved by SDS-PAGE, and WB membranes were probed with the appropriate antibodies. A The bar histograms depict the level of ERK divided by Actin, rats treated with cocaine (15 mg/kg) displayed significantly lower values compared to all other groups (P < 0.001), as determined by a two-way ANOVA test [FOPTIC STIMULATION (1,29) = 9.199, P < 0.01, FGROUP(1,29) = 10.13, P < 0.01, FINTERACTION (1,29) = 9.441, P < 0.01, followed by Tukey’s multiple comparison test]. (n = 8, 7, 9, and 9 for saline -, saline +, cocaine-, and cocaine+ groups, respectively). B The bar histograms depict the level of pERK (Thr202/Tyr204) divided by ERK protein, rats treated with cocaine (15 mg/kg) displayed significantly higher values compared to all other groups (P < 0.001), as determined by a two-way ANOVA test [FOPTIC STIMULATION (1,16) = 5.075, P < 0.05, FGROUP(1,16) = 12.3, P < 0.01, FINTERACTION (1,16) = 22.18, P < 0.001, followed by Tukey’s multiple comparison test]. (n = 5 for all groups). C The bar histograms depict the level of GluA1 divided by Actin. No significant difference was found [FOPTIC STIMULATION (1,18) = 1.112, P > 0.05, FGROUP(1,18) = 3.486, P > 0.05, FINTERACTION (1,18) = 2.292, P > 0.05, two-way ANOVA followed by Tukey’s multiple comparison test]. (n = 5 for the saline groups, n = 6 for the cocaine groups). D The bar histograms depict the level of GluA1ps845 divided by GluA1 protein, rats treated with cocaine (15 mg/kg) displayed significantly higher values compared to saline-treated rats (P < 0.05), as determined by a two-way ANOVA test [FOPTIC STIMULATION (1,17) = 0.5023, P > 0.05, FGROUP(1,17) = 2.699, P > 0.05, FINTERACTION (1,17) = 7.414, P < 0.05, followed by Tukey’s multiple comparison test]. (n = 4, 5, 6, and 6 for saline–, saline +, cocaine-, and cocaine+ groups, respectively). E The bar histograms depict the level of GluA1ps831 divided by GluA1 protein, rats treated with cocaine (15 mg/kg) with optic stimulation displayed significantly lower values compared to the saline with optic stimulation and saline without optic stimulation groups (P < 0.05), as determined by a two-way ANOVA test. A nonsignificant reduction was found in the cocaine-treated group compared to the saline with optic stimulation and saline without optic stimulation groups [FOPTIC STIMULATION (1,14) = 0.3760, P > 0.05, FGROUP(1,14) = 14.33, P < 0.01, FINTERACTION (1,14) = 0.9373, P > 0.05, followed by Tukey’s multiple comparison test]. (n = 4 for the saline groups, n = 5 for the cocaine groups). (Off refers to - optic stimulation, whereas +On refers to +optic stimulation).
