Figure 10.

Overexpression of pHluorin-GluR1-S845A mutant blocked the morphine-regulated AMPA receptors internalization. A, Neurons coexpressing DsRed and pHluorin-GluR1-WT (top) or pHluorin-GluR1-S845A (bottom) were imaged before (left) and after (right) morphine treatment (10 μm for 1 d). Open arrowheads denote no change in pHluorin-GluR1 and spine morphology. Solid arrowheads denote loss of surface pHluorin-GluR1 (green fluorescence) and shrinkage of spines (DsRed fluorescence) by morphine. Scale bar, 10 μm. B, Averaged fluorescence of pHluorin-GluR1 from different regions of neurons (entire image, spines, and dendritic shafts) were normalized to values before treatment in the four groups of experiments (WT/Ctl, overexpression of pHluorin-GluR1-WT with no drug; WT/Mor, pHluorin-GluR1-WT with morphine; S845A/Ctl, pHluorin-GluR1-S845A with no drug; S845A/Mor, pHluorin-GluR1-S845A with morphine). *p < 0.05, comparing with data before treatment. At least five dendrites of single neurons were analyzed (n = 10 in each group). Error bars represent ± SEM.