Strain Differences in Autotomy in Rats Undergoing Sciatic Nerve Transection or Repair

Mm, Carr; Best, Timothy J.; Mackinnon, Susan E.; Evans, Peter

doi:10.1097/00000637-199228060-00008

Cited by 104 publications

(36 citation statements)

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“…Autotomy was not observed in any of the animals, supporting previous conclu-sions [Carr et al, 1992] and observations [Chamberlain et al, 1998] concerning the absence of self-mutilation following nerve transection in Lewis rats. Over the course of the 9 week experiment, 1 animal (device group B) died of unknown causes.…”

Section: General Observationssupporting

confidence: 89%

“…Twenty-seven adult female Lewis rats (Charles River Laboratories, Wilmington, Mass., USA), 175-200 g, were used in this study. The Lewis strain of rat was chosen because of its resistance to autotomy, or self-mutilation, following sciatic nerve transection [Carr et al, 1992]. Six animals were implanted with each of the devices A-D, while only 3 animals were implanted with device E (table 1).…”

Section: Animal Modelmentioning

confidence: 99%

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Optimal Degradation Rate for Collagen Chambers Used for Regeneration of Peripheral Nerves over Long Gaps

Harley

Spilker

et al. 2004

Cells Tissues Organs

117

106

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The experimental study of peripheral nerve regeneration has depended heavily on the use of a nerve chamber in which the stumps of the transected nerve are inserted. A large variety of chamber fillings and chamber types have been used in an effort to induce a higher quality of regeneration across the gap initially separating the two stumps. In this study we studied the morphology of nerves regenerated across a 15 mm gap following implantation of a series of five chambers. The chambers were fabricated from type I collagen and possessed identical pore volume fractions as well as average pore diameters, but differed in cross-link density continuously along the series. The residual mass of the implanted chambers at 9 weeks was observed to increase continuously with increasing cross-link density along the series, indicating a continuous decrease in degradation rate. The quality of regenerated nerves, determined by the number of large diameter fibers (A-fibers) per nerve, the average diameter of all axons and the ratio of area occupied by axons (N-Ratio), was superior at an intermediate level of chamber degradation rate. The maximal quality of peripheral nerve regeneration corresponded to an optimal degradation rate with an estimated chamber half-life of approximately 2–3 weeks following implantation. A speculative mechanistic explanation of the observed optimum focuses on the hypothetical role of cell and cytokine traffic that may take place through holes in the chamber generated by the degradation process. The data show the presence of a hitherto unreported optimal chamber degradation rate that leads to regenerated nerves of maximum quality.

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Section: General Observationssupporting

confidence: 89%

Section: Animal Modelmentioning

confidence: 99%

Optimal Degradation Rate for Collagen Chambers Used for Regeneration of Peripheral Nerves over Long Gaps

Harley

Spilker

et al. 2004

Cells Tissues Organs

117

106

View full text Add to dashboard Cite

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“…Chronic limb retractions, contractures and the occurrence of autotomy may impair the ability to use such method 1,2,10 . In our study, these complications affected 42 % of the rats, but can occur in up to 88% of the animals, making it unfeasible to use walking-track analysis in some studies [12][13][14][15] . The incidence of autotomy was found to be related to the type of injury, being more frequent in association with nerve section -the model used in our study -than with crush lesions.…”

Section: Discussionmentioning

confidence: 99%

Correlation between parameters of electrophysiological, histomorphometric and sciatic functional index evaluations after rat sciatic nerve repair

Martins

Siqueira

Silva

et al. 2006

Arq. Neuro-Psiquiatr.

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-The rat sciatic nerve is a well-established model for the study of recovery from peripheral nerve injuries. Traditional methods of assessing nerve regeneration after nerve injury and repair, such as electrophysiology and histomorphometry, despite widely used in neural regeneration experiments, do not necessarily correlate with return of motor and sensory functions. The aim of this experimental study is to investigate the possible correlation between several parameters of peripheral nerve regeneration after repair of sectioned sciatic nerve in Wistar rat. A two-stage approach was used to obtain 17 parameters after electrophysiological, morphometric and sciatic functional index evaluations. Pearson's correlation analysis was performed between these results. Only two positives correlations between different classes of peripheral nerve assessments were noted, between sciatic functional index and proximal nerve fiber diameter (r=0.56, p<0.01) and between sciatic functional index and distal fiber diameter (r=0.50, p<0.01). The data presented in our study demonstrates that there is a poor correlation between the sciatic functional index and outcome measures of electrophysiological and morphometric evaluations.KEY WORDS: nerve repair, sciatic functional index, rat sciatic nerve, nerve regeneration, nerve morphometry.Correlações entre parâmetros obtidos das avaliações eletrofisiológica, histomorfométrica e do índice funcional ciático após o reparo do nervo ciático do rato RESUMO -O nervo ciático do rato é o modelo mais amplamente utilizado para o estudo da regeneração após uma lesão de nervo. Apesar do uso amplo para a avaliação da regeneração os métodos tradicionais, como a avaliação eletrofisiológica e histomorfométrica, nem sempre apresentam correlações com a recuperação motora e sensitiva. O objetivo deste estudo é investigar as possíveis correlações entre vários parâmetros da regeneração após a secção e reparo do nervo ciático do rato. Foi utilizado um experimento dividido em dois estágios para obter 17 parâmetros após a realização de avaliações eletrofisiológica, histomorfométrica e funcional. A análise das possíveis correlações foi obtida através da aplicação do méto-do de Pearson. Somente duas correlações positivas entre diferentes tipos de avaliações foram obtidas, entre o índice funcional ciático e o diâmetro proximal das fibras (r=0,56, p<0,01) e entre o índice funcional ciáti-co e o diâmetro distal das fibras (r=0,50, p<0,01). Concluímos que as correlações entre diferentes métodos de avaliação da regeneração no nervo ciático do rato são pouco freqüentes. PALAVRAS-CHAVE: reparo do nervo, índice funcional ciático, nervo ciático do rato, regeneração nervosa, morfometria do nervo.The rat sciatic nerve is the most used model for evaluation of experimental peripheral nerve regeneration 1,2 . This occurs because rat sciatic nerve regeneration is extremely efficient and fast and this model has a relative low cost . In addition, this model permits assessment of nerve regeneration after repair using several t...

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“…67 To circumvent this potential problem, Lewis rats could be used as an alternative for future walking track studies, since it has been suggested that this strain is less prone to autophagia than are Fischer rats. 12,21,30,39 Our laboratory has performed reversed autografts in male Lewis rats by following the same protocol applied in the current study, with 4-and 16-week survival times. The Lewis rats displayed little to no autotomy behavior.…”

Section: Walking Track Analysis Sfi and Autotomy Scoresmentioning

confidence: 99%

Transplantation of Schwann cells in a collagen tube for the repair of large, segmental peripheral nerve defects in rats

Berrocal

Almeida

Gupta

et al. 2013

JNS

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Object Segmental nerve defects pose a daunting clinical challenge, as peripheral nerve injury studies have established that there is a critical nerve gap length for which the distance cannot be successfully bridged with current techniques. Construction of a neural prosthesis filled with Schwann cells (SCs) could provide an alternative treatment to successfully repair these long segmental gaps in the peripheral nervous system. The object of this study was to evaluate the ability of autologous SCs to increase the length at which segmental nerve defects can be bridged using a collagen tube. Methods The authors studied the use of absorbable collagen conduits in combination with autologous SCs (200,000 cells/μl) to promote axonal growth across a critical size defect (13 mm) in the sciatic nerve of male Fischer rats. Control groups were treated with serum only–filled conduits of reversed sciatic nerve autografts. Animals were assessed for survival of the transplanted SCs as well as the quantity of myelinated axons in the proximal, middle, and distal portions of the channel. Results Schwann cell survival was confirmed at 4 and 16 weeks postsurgery by the presence of prelabeled green fluorescent protein–positive SCs within the regenerated cable. The addition of SCs to the nerve guide significantly enhanced the regeneration of myelinated axons from the nerve stump into the proximal (p < 0.001) and middle points (p < 0.01) of the tube at 4 weeks. The regeneration of myelinated axons at 16 weeks was significantly enhanced throughout the entire length of the nerve guide (p < 0.001) as compared with their number in a serum–only filled tube and was similar in number compared with the reversed autograft. Autotomy scores were significantly lower in the animals whose sciatic nerve was repaired with a collagen conduit either without (p < 0.01) or with SCs (p < 0.001) when compared with a reversed autograft. Conclusions The technique of adding SCs to a guidance channel significantly enhanced the gap distance that can be repaired after peripheral nerve injury with long segmental defects and holds promise in humans. Most importantly, this study represents some of the first essential steps in bringing autologous SC-based therapies to the domain of peripheral nerve injuries with long segmental defects.

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Strain Differences in Autotomy in Rats Undergoing Sciatic Nerve Transection or Repair

Cited by 104 publications

References 0 publications

Optimal Degradation Rate for Collagen Chambers Used for Regeneration of Peripheral Nerves over Long Gaps

Optimal Degradation Rate for Collagen Chambers Used for Regeneration of Peripheral Nerves over Long Gaps

Correlation between parameters of electrophysiological, histomorphometric and sciatic functional index evaluations after rat sciatic nerve repair

Transplantation of Schwann cells in a collagen tube for the repair of large, segmental peripheral nerve defects in rats

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