Downregulation of surface GABAAR γ2 levels in response to TNFα is blocked by inhibitors of PI3K, p38 MAPK, and PP1/PP2A. A, Representative dendritic regions of surface immunostaining for GABAAR γ2 subunit, from control (Ctrl) versus TNFα-treated (100 ng/ml, 45 min) cultured neurons, preincubated with DMSO (solvent, 0.1%) or inhibitors of PKA [KT 5720 (KT), 1 μm], PKC [Gö 6983 (Gö), 1 μm], PI3K [wortmannin (Wortm), 100 nm], p38 MAPK [SB 202190 (SB), 10 μm], calcineurin [cyclosporin A (CsA), 20 μm], and PP1/PP2A (okadaic acid (OKA), 0.05 or 0.5 μm). Scale bar, 3 μm. B, Quantification data corresponding to conditions in A, indicating that TNFα-induced downregulation of surface γ2 cluster area is blocked by preincubation with wortmannin, SB 2022190, and 0.5 μm okadaic acid but not KT 5720, Gö 6983, cyclosporin A, or 0.05 μm okadaic acid (n = 60–228 images in each condition; two-way ANOVA, Bonferroni's post hoc test, *p < 0.05, **p < 0.01, ***p < 0.001; n.s., not significant).