Morphometric analysis of early regeneration of motor axons through motor and cutaneous nerve grafts

N. Ghalib et al., Morphometric analysis of early regeneration of motor axons through motor and cutaneous nerve grafts, ANN ANATOMY, 183(4), 2001, pp. 363-368
Citations number
Categorie Soggetti
Experimental Biology
Journal title
ISSN journal
0940-9602 → ACNP
Year of publication
363 - 368
SICI code
Peripheral nerve damage is a frequent consequence of trauma, tumor surgery or diseases. Clinical results of functional reinnervation after the applica tion of cutaneous grafts are still unsatisfactory. Differences in the extra cellular matrix are considered to be one of the factors responsible for poo r results of motor axon reinnervation through the cutaneous graft. To verif y these differences, we compared morphological features of the motor axons regenerating through the graft prepared from the saphenous nerve and the mo tor branch of the femoral nerve. Eighteen female adult rats (Wistar) were u sed in experiments. The saphenous nerve, the femoral nerve, and its main mo tor branch were exposed under deep anesthesia with ketamine and xylazine. T he nerve graft (10 mm) prepared from the saphenous nerve was applied betwee n the stumps of the transected motor branch of the femoral nerve in the 6 r ats. In the next 6 rats, the nerve graft (10 mm) harvested from the motor b ranch of the femoral nerve was inserted between stumps of the transected mo tor branch of the femoral nerve on the contralateral side. All rats were perfused with Zamboni's fixative solution 14 days after graft ing. The samples of grafts and the intact motor branch (n = 6) were dissect ed and embedded in Durcupan ACM. Semithin sections stained with Toluidine B lue were used for morphometric analysis of myelinated axons by means of com puter-assisted image analysis system. Ultrathin sections counterstained wit h uranyl acetate were viewed and photographed in an electron microscope. Th e number of myelinated motor axons showing early regeneration under conditi ons of the cutaneous an motor nerve grafts was similar. The diameter of axo ns and thickness of their myelin sheaths were significantly smaller when th e axons regenerated into the saphenous nerve in contrast to the motor graft . Morphometric analysis of early regeneration of myelinated motor axons sug gests that the cutaneous and motor branches of the femoral nerve provide di fferent conditions not for the growth but for the maturation of motor axons .