Fig. 1. Expression and distribution of synaptic GluR1 and GluR2 in dorsal horn of naïve rats. (A , B ) Representative photographs showing that GluR1 immunoreactivity is distributed mainly in laminae I and II and that GluR2 immunoreactivity is predominantly in lamina II. Scale bar: 200 μm. (C , D ) Examples of postsynaptic immunogold labeling for GluR1 and GluR2 in superficial dorsal horn synapses illustrate labeling in the synapses. Post = postsynaptic structure; Pre = presynaptic terminals. Scale bar: 100 nm.