Figure 2.
The expression of Nav1.7 is increased in nociceptive DRG neurons in rats with paclitaxel-treated CIPN. Representative IHC images are shown in A–H. A, B, The expression of Nav1.7 (red) in DRGs is normally low in naive (data not shown) and vehicle-treated rats (A) but becomes greatly increased by day 7 after paclitaxel treatment (B). C–H, Nav1.7 is colocalized in subsets of IB4-positive (green) neurons (C, D, colocalization indicated in yellow) and CGRP-positive (blue) neurons (E, F, colocalization indicated in purple), as well as in a percentage of neurons negative for both IB4 and CGRP (G, H, overall merged). I–K, The bar graphs summarize the grouped IHC data and show that the overall number of Nav1.7-positive neurons (I) was significantly higher in the paclitaxel-treated rats (black bars) than in the vehicle-treated rats (white bars); and these increases were significantly higher in neurons with diameters <30 μm and to a lesser extent in medium-sized (30–45 μm) DRG neurons (J); and in IB4-positive and CGRP-positive neurons, as well as neurons negative for both markers (K). Scale bar, 100 μm. *p < 0.05, ***p < 0.001.