Fig. 4.

SP-immunopositive nerve fibers in the ventral (a, c, e) and dorsal (b, d, f) dura mater lumbalis of controls (a, b), laminectomized rats (c, d), and animals that underwent laminectomy and application of free autologous fat grafts (e, f); light microscopic micrographs of whole-mount preparations. a Small bundles of nerve fibers and single neurons innervating the ventral dura. Some of them (arrows) accompany delicate meningeal blood vessels. A few nerve fibers terminate at or close to the blood vessels (arrowheads) others end up in the connective tissue (open arrowheads). b Single nerve fiber with a straight thickened terminal (arrowhead) in the connective tissue of the dorsal dura. c Dense network of immunopositive nerve fibers in the ventral dura mater lumbalis. Note the prominent varicosities. d Dense innervation of the dorsal dura mater lumbalis after laminectomy. Immunopositive nerve fibers are predominantly arranged parallel to the dorsal midline. e Widespread fiber network in the ventral dura. f Network of stained nerve fibers running in parallel to the dorsal midline. Note one fiber (arrow) that extends from the ventral dura to the dorsal parts and arborizes along the midline. dm dorsal midline, MV meningeal blood vessels. Bars 100 μm