Upregulation of 5-HT2C receptor clusters after SCI. A, B, 5-HT2C immunoreactivity from intact (A) and SCI (B) slices in the medial lamina VIII, imaged at the same fluorescence intensity. C–E, SCI significantly increases the number of 5-HT2C receptor clusters (C) and the average area of 5-HT2C receptor clusters (D), but not the intensity of 5-HT2C receptor clusters (E) compared with intact slices. *p < 0.01, data in C–E are means from 13 pairs of intact and SCI mice. Scale bars: 10 μm.