Figure 5

Distribution of p75 immunoreactivity following nerve injury and relationship to nerve fibers and proNGF. A) In sham-operated animals, p75 was distributed (red) around and with PGP 9.5-IR nerve fibers (green). P75 staining was found more clearly around large cutaneous PGP 9.5-IR nerve fiber bundles and smaller fibers along the dermo-epidermal junction. Where nerve fibers crossed the dermo-epidermal junction into the epidermis, the yellow color representing p75 associating with nerve fibers was lost (arrow). B) At 1 week post-injury, virtually all PGP-9.5-IR nerve fibers disappeared from the upper dermis and epidermis; immunostaining in p75-IR Schwann was very intense. C) At 2 weeks post-injury, a low number of PGP-9.5-IR fibers were detected and were associated with p75 Schwann cells (yellow), however most of the PGP-9.5-IR was restricted to Langerhans cells in epidermis (arrow) D) At 4 weeks post-injury, p75 immunoreactivity decreased co-incidentally with the increase in PGP-9.5 immunoreactivityin the upper dermis (yellow). E-H) ProNGF and p75 association in sham-operated controls and in lesioned animals was loose in that most proNGF immunoreactivity was segregated from that for p75 and there was no obvious co-localization (arrows).