Comparison of the Nerve Regeneration Capacity and Characteristics between Sciatic Nerve Crush and Transection Injury Models in Rats.

ABSTRACT

Objective: To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies, and to compare nerve regeneration capacity and characteristics between them. Methods: Sixty adult SD rats were randomly divided into two groups and underwent crush injury alone (group A, n = 30) or transection injury followed by surgical repair (group B, n = 30) of the right hind paw. Each group was subjected to the CatWalk test, gastrocnemius muscle evaluation, pain threshold measurement, electrophysiological examination, retrograde neuronal labeling, and quantification of nerve regeneration before and 7, 14, 21, and 28 days after injury. Results: Gait analysis showed that the recovery speed in group A was significantly faster than that in group B at 14 days. At 21 days, the compound muscle action potential of the gastrocnemius muscle in group A was significantly higher than that in group B, and the number of labeled motor neurons in group B was lower than that in group A. The number of new myelin sheaths and the g-ratio were higher in group A than in group B. There was a 7-day time difference in the regeneration rate between the two injury groups. Conclusion: The regeneration of nerve fibers was rapid after crush nerve injury, whereas the transection injury was relatively slow, which provides some ideas for the selection of clinical research models.