Immunoreactivity for PGP9.5 (40x). A. Control group, Β. POD 1, C. POD 3, D. POD 5, E. 1 Week post-PH, F. 2 weeks post-PH, G. 1 month post-PH, H. 3 months post-PH, I. 6 months post-PH. Increased density of nerve fibers at the control group, in the form of dots and small nerve bundles (arrows), as well as at 1, 3 and 6 months post-PH, in the form of dots (arrows) and nerve bundles (arrow heads).