Figure 3.
Dorsal horn GluR2 internalization after CFA injection. GluR2 expression in 150 k-g spin fraction (A) and plasma membrane fraction (B) from ipsilateral dorsal horn at 2 h, 1 d, and 3 d after saline or CFA. Top, Representative Western blots; bottom, statistical summaries of the densitometric analysis expressed relative to the naive animals (0 h). *p < 0.05, **p < 0.01 versus the naive group. C, Surface expression of GluR2 and NR1 in dorsal horn neurons at 1 d after CFA or saline. Top, Representative Western blot; bottom, statistical summary of the densitometric analysis. The amount of sample loaded for the total (T) was 10% of that for the biotinylated surface (S). *p < 0.05 versus the saline-treated group. α-Actin, an unbiotinylated intracellular protein, was used as a control. D, Examples of postsynaptic immunogold labeling for GluR2 in superficial dorsal horn synapses illustrate labeling (arrowheads) in both the synapse and adjacent cytoplasmic structures 1 d after saline and only in cytoplasm 1 d after CFA. Pre, Presynaptic terminal; Post, postsynaptic structure. Scale bars, 100 nm.