title: Retrograde tracing and toe spreading after experimental autologous nerve transplantation and crush injury of the sciatic nerve: a descriptive methodological study.
abstract: Evaluation of functional and structural recovery after peripheral nerve injury is crucial to determine the therapeutic effect of a nerve repair strategy. In the present study, we examined the relationship between the structural evaluation of regeneration by means of retrograde tracing and the functional analysis of toe spreading. Two standardized rat sciatic nerve injury models were used to address this relationship. As such, animals received either a 2 cm sciatic nerve defect (neurotmesis) followed by autologous nerve transplantation (ANT animals) or a crush injury with spontaneous recovery (axonotmesis; CI animals). Functional recovery of toe spreading was observed over an observation period of 84 days. In contrast to CI animals, ANT animals did not reach pre-surgical levels of toe spreading. After the observation period, the lipophilic dye DiI was applied to label sensory and motor neurons in dorsal root ganglia (DRG; sensory neurons) and spinal cord (motor neurons), respectively. No statistical difference in motor or sensory neuron counts could be detected between ANT and CI animals.In the present study we could indicate that there was no direct relationship between functional recovery (toe spreading) measured by SSI and the number of labelled (motor and sensory) neurons evaluated by retrograde tracing. The present findings demonstrate that a multimodal approach with a variety of independent evaluation tools is essential to understand and estimate the therapeutic benefit of a nerve repair strategy.
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Sabien Ga
authors.initials: SG
authors.lastname: van Neerven
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Bozkurt
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Dan Mon
authors.initials: DM
authors.lastname: O'Dey
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Scheffel
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Arne H
authors.initials: AH
authors.lastname: Boecker
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Jan-Philipp
authors.initials: JP
authors.lastname: Stromps
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Dunda
authors.affiliation: Institute of Neuropathology, Medical Faculty, RWTH Aachen University, Aachen, Germany.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Brook
authors.affiliation: Department of Plastic Surgery, Reconstructive and Hand Surgery, Burn Center, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Pallua