Investigation into a new denervation model of the sciatic nerve zones in rats: Selective motor or sensorial denervation

Abstract

Objective: This study aimed to introduce a reliable and useful model of selective sensorial or motor denervations of the sciatic nerve in rats with clinical and laboratory outcomes. Methods: The surgical technique was determined via detailed cadaveric dissections of rat sciatic nerve roots and cross-sectional histoanatomy. Forty animals were divided into the sham, sensorial denervation (SD), motor denervation (MD), and combined denervation (CD) groups and evaluated clinically via the pinch test and observation. Electrophysiological tests, retrograde neuronal labeling, and histologic and radiographic studies were performed. The weights of the muscles innervated by the sciatic nerve were measured. Results: The nerve root topography at the L4 level was consistent. Hemilaminectomy satisfactorily exposed all the roots contributing to the sciatic nerve and selectively denervated its sensorial and motor zones. Sensorial denervation caused foot deformities and wound problems, which were more severe in SD than in MD and CD. Nerve histomorphometry, electrophysiological tests, retrograde neuronal labeling studies, and measurements of the muscle weights also verified the denervations. Conclusion: This study has shown the feasibility of selective (sensory or motor) sciatic nerve denervation through a single-level hemilaminectomy. The surgical technique is reliable and has a confounding effect on gait. Sensorial denervation had more severe foot problems than motor and combined denervation in rats.