Fig 2: CaMKII pT305/306 promotes LTD-induced GABAAR insertion at inhibitory synapses.Quantifications show means ± SEM. *P < 0.05 and **P < 0.01. Scale bars, 10 µm. (A) Schematic of CaMKII movement in response excitatory LTD stimuli. The LTD-induced pT305/306 blocks CaMKII movement to glutamatergic excitatory synapses and instead enables movement to GABAergic inhibitory synapses. (B) cLTD stimulation increased surface GABAAR accumulation in WT, but not T305/6AV, CA1 mini-slices (unpaired two-tailed t test, P = 0.0033 for WT and P = 0.6760 for AV, n = 5 and 6 samples (two slices/sample), as detected by immunoblot after surface biotinylation. (C) cLTD stimulation decreased surface GluA1 accumulation in WT, but not T305/6AV, CA1 mini-slices (unpaired two-tailed t test, P = 0.0062 for WT and P = 0.6252 for AV, n = 5 and 6 samples (two slices/sample). (D) cLTP decreased surface GABAAR cluster size in nonpermeabilized neurons from WT mouse hippocampal cultures (fixed 5 min after washout), while cLTD increased the cluster size (fixed 20 min after washout) (one-way ANOVA, Tukey’s post hoc test versus control, P = 0.0273 for cLTP and P = 0.0046 for cLTD; n = 12, 12, and 13 neurons), as detected by immunocytochemistry. (E) By contrast, in nonpermeabilized neurons from T305/5AV hippocampal cultures, cLTD did not increase surface GABAAR clusters. However, cLTP still decreased surface GABAAR clusters (P = 0.0147 for cLTP and P = 0.7121 for cLTD; n = 15, 13, and 14 neurons).

Fig 3: The effect of DPCPX on GluA1 phosphorylation in the rat mPFC and hippocampus. (a) The effect of DPCPX on GluA1 phosphorylation and expression in the mPFC. (b) The effect of DPCPX on GluA1 phosphorylation and expression in the hippocampus (Hippo). Note that DPCPX at a higher dose (2.5 mg/kg) but not a lower dose (0.25 mg/kg) induced an increase in pS845 levels in the mPFC and hippocampus. Representative immunoblots are shown left to the quantified data. Rats were administered with vehicle or DPCPX at either 0.25 or 2.5 mg/kg (i.p.) and were then sacrificed 20 min after drug administration for subsequent analysis of changes in S845 and S831 phosphorylation using Western blots. Data are presented as means ± SEM (n = 4 per group) and were analyzed using one-way ANOVA: mPFC-pS845, F(2,9) = 4.92, p = .036; mPFC-pS831, F(2,9) = 0.17, p = .844; mPFC-GluA1, F(2,9) = 1.38, p = .300; hippocampus-pS845, F(2,9) = 5.27, p = .031; hippocampus-pS831, F(2,9) = 0.22, p = .804; and hippocampus-GluA1, F(2,9) = 0.54, p = .599. *p < .05 versus vehicle

Fig 4: The effect of DPCPX on GluA1 phosphorylation in the rat CPu and NAc. (a) The effect of DPCPX on GluA1 phosphorylation and expression in the CPu. (b) The effect of DPCPX on GluA1 phosphorylation and expression in the NAc. Note that DPCPX at a higher dose (2.5 mg/kg) but not a lower dose (0.25 mg/kg) induced an increase in pS845 levels in both the CPu and NAc. Representative immunoblots are shown left to the quantified data. Rats were administered with vehicle or DPCPX at either 0.25 or 2.5 mg/kg (i.p.) and were then sacrificed 20 min after drug administration for subsequent analysis of changes in S845 and S831 phosphorylation using Western blots. Data are presented as means ± SEM (n = 4 per group) and were analyzed using one-way ANOVA: CPu-pS845, F(2,9) = 6.15, p = .021; CPu-pS831, F(2,9) = 0.25, p = .785; CPu-GluA1, F(2,9) = 0.05, p = .949; NAc-pS845, F(2,9) = 8.29, p = .009; NAc-pS831, F(2,9) = 0.23, p = .801; and NAc-GluA1, F(2,9) = 1.79, p = .222. *p < .05 versus vehicle

Fig 5: The effect of SCH23390 on DPCPX-induced GluA1 S845 phosphorylation in the rat mPFC and hippocampus. (a) The effect of SCH23390 on DPCPX-induced S845 phosphorylation in the mPFC. (b) The effect of SCH23390 on DPCPX-induced S845 phosphorylation in the hippocampus (Hippo). Note that SCH23390 completely blocked the DPCPX-induced S845 phosphorylation in the two regions. Representative immunoblots are shown left to the quantified data. Rats were administered with SCH23390 (SCH, 0.1 mg/kg, i.p.) 10 min prior to DPCPX (2.5 mg/kg, i.p.) and were then sacrificed 15–20 min after DPCPX administration for subsequent analysis of changes in S845 and S831 phosphorylation using Western blots. Data are presented as means ± SEM (n = 4 per group) and were analyzed using two-way ANOVA: mPFC-pS845: saline versus SCH23390, F(1,12) = 33.01, p < .001, vehicle versus DPCPX, F(1,12) = 4.14, p = .064, and interaction, F(1,12) = 7.18, p = .020; and hippocampus-pS845: saline versus SCH23390, F(1,12) = 59.25, p < .001, vehicle versus DPCPX, F(1,12) = 18.87, p = .001, and interaction, F(1,12) = 10.74, p = .007. *p < .05 versus saline + vehicle. + p < .05 versus saline + DPCPX