FIGURE 5.

CaMKII and ERK1/2 are involved in intracellular mGluR5-mediated Arc up-regulation. A and B, striatal neurons were treated with Quis (red) in the absence or presence of indicated antagonists (KN62, general CaMK antagonist, 10 μm; KN93, specific CaMKII antagonist, 10 μm; STO609, CaMKK inhibitor, 1.5 μm; U0126, MEK/ERK1/2 antagonist, 1 μm; LY294002, PI3K antagonist, 50 μm; wortmannin, PI3K antagonist, 500 nm; rapamycin, mTOR antagonist, 5 nm; CysA, cyclosporin A, calcineurin antagonist, 4 μm) for 1 h, fixed, and stained for Arc and neuronal nuclei (NeuN). Bars represent quantitation of Arc immunofluorescence in neurons (expressed as % of Quis treatment) from n = 3–5 independent experiments; *, p < 0.001 versus Quis; #, p < 0.001 versus control. More than 3000 neurons per treatment condition were assessed. Gray bars indicate untreated neurons or neurons treated with indicated antagonists in absence of Quis. C, plasmid encoding EGFP alone or EGFP-labeled dominant negative CaMK constructs as indicated were transiently transfected in striatal neurons (green), and 24 h post-transfection neurons were treated with Quis for 1 h, fixed, and stained with Arc (red) and mGluR5 (blue). D, shown is quantitation of Arc immunofluorescence in terms of number of Arc-positive neurons (expressed as % of EGFP alone transfected neurons) from n = 5 independent experiments; a total of >250 neurons/plasmid was assessed. *, p < 0.05 compared with EGFP alone.