Figure 1.

Representative examples of 50 μm sections from skin biopsies immunostained for GAP-43. Healthy control (A) shows numerous long branching intraepidermal nerve fibers (red arrows) reaching upper layers of epidermis and well-developed sub-epidermal nerve plexus (green arrows). Biopsy from a PD patient (B) showing scant, faintly staining intraepidermal nerve fibers (red arrows), and scant subepidermal plexus (green arrows). Images (C–E) show examples of axonal swellings along the IENFs and sub-epidermal nerve fibers (F) (yellow arrows). Images (G–I) show focal accumulations of nerve fibers in subepidermal area, which give rise only to occasional NFs crossing the BM into the epidermis (red arrows). Such areas are often separated by stretches of papillary dermis with very scant subepidermal plexus as in (B). (A–I) were taken at the same magnification ×200, scale bar = 100 μm.