Figure 4.

TNFα does not increase the surface expression of GluR2. A, Representative micrographs from cultured neurons double labeled for surface GluR1 and GluR2, after treatment with TNFα. Despite a clear increase in GluR1 surface expression, GluR2 surface levels are not increased relative to untreated cultures. B, Quantification of all doubled-labeled cells, showing a significant increase in GluR1 surface expression after TNFα treatment (black bars; n = 177) compared with untreated cells (gray bars; n = 156), whereas the same cells had no significant increase in GluR2 surface expression relative to untreated controls. C, Representative blots from surface biotinylation experiments from sister cultures, probed for GluR1 or GluR2, after treatment with TNFα. D, Quantification of all experiments for the levels of biotinylated receptors (n = 7 cultures for GluR1, 6 for GluR2).