FIG. 5.

Integrity of repaired roots. Photomicrographs of longitudinally sectioned ventral and dorsal roots and adjacent spinal nerves showing integrity of repair site. (A) Examination of hematoxylin and eosin (H&E)–stained root bundle of one animal reveals excellent healing across the site of reanastomosis. Small black arrows indicate sutures. (B) Neurofilament immunofluorescence staining (red) of a nearby section of same animal as shown in A shows continuity of axons across the site of repair. White arrow indicates a suture. (C) H&E staining of a root from another animal that had received brain-derived neurotrophic factor (BDNF) from a cuff at the site of root repair shows a separation between proximal (upper half of picture) and distal (lower half of picture) stumps. The root is surrounded by clumps of inflammatory cells (indicated by asterisk). (D) Neurofilament immunostaining of an adjacent section of root as shown in panel C, reveals axons growing around the scar site (black arrowheads trace the path of the neurofilament stained axons). (E,F) Higher-power examination of inflammatory site indicated by the asterisk in panel C reveals leukocytes (indicated as L in panel E, H&E staining), as well as macrophages (mac) and neutrophils (n; F, Hema 3 stain). Scale bar = 50 μm.