1.7 expression in axon bundles. A-D. Confocal micrographs of single optical images showing Nav1.7 (red) expression within N52 (green) and PGP9.5 (blue)-identified nerve fibers within axon bundles in normal (A, B) and painful (C, D) samples. A and B. Nav1.7 (red; arrows) is expressed in nerve fibers that appear intact as visualized with PGP9.5 and especially N52 (green) staining within an axon bundle located in a normal sample (A), while a different normal sample shows some fibers that appear fragmented as seen with N52 staining (B; arrow). C and D. The expression of Nav1.7 within a painful sample (C) appears prominent within intact nerve fibers (arrows), but less in fibers that appear fragmented (arrowheads) as visualized with N52 staining. A different painful sample contains many fibers with prominent Nav1.7 staining, including some that show minimal staining with N52 and PGP9.5 (D; arrow). Scale bars = 20 μm in A-C and 100 μm in D.