Korean J Phys Anthropol.  2012 Mar;25(1):11-21.

Comparative Study of the L5 Spinal Nerve Transection Model and Sciatic Nerve Axotomy Model as a Peripheral Nerve Injury Model in Rat

• Song DY
• Lee JH
• Yu HN
• Park CR
• Woo RS
• Hong SY
• Cheon YH
• Goo HN
• Baik TK

Abstract

The aim of this study was to propose new more reliable peripheral nerve transection model to overcome the defect of the traditional sciatic axotomy model by specifically transecting L5 spinal nerve just after emerging from the intervertebral foramen and confining analysis area to the L5 spinal segment. The adult male Sprague-Dawley rats, weighing 300~350 g at the time of surgery, were used for the experiments. Four different experimental groups were used. 1. Sciatic nerve transection (Sc-Tx) group: transect the sciatic nerve in the popliteal fossa where it divided into the common peroneal nerve and tibial nerve. 2. L5 spinal nerve transection (L5-Tx) group: L5 spinal nerve was specifically transected. 3. Suture (Su) group: L5 spinal nerve was transected and immediately sutured. 4. Control group: the same surgical procedure with L5 spinal nerve transection group was performed except for the excision of L5 spinal nerve. To distinguish L5 motoneurons from the other level ones, the animals were received the retrograde tracer, FluoroGold into the axotomized proximal nerve stump. Serial coronal frozen sections at 40 microm thick through the L4 to L6 spinal segment was performed and the resultant total number of sections was about 180. Approximate serial 50 sections (approximately 2 mm) could be considered as the L5 segment based on the number of the fluorescent signals (above 20). L5 spinal segment could be differentiated from L4 and L6 segment based on their morphological characteristics under Cresyl violet stain. In L5-Tx group, at 2 and 4 weeks post-transection, the number of L5 spinal motoneurons was reduced by 8%. Meanwhile, Sc-Tx and Su groups showed no statistically notable changes. In this study, the authors could propose more reliable peripheral nerve axotomy model than the conventional sciatic nerve axotomy model by specifically transecting L5 spinal nerve and confining the investigating area within the L5 spinal segment.

Keyword

Peripheral nerve transection; L5 spinal nerve; Spinal motoneuron; FluoroGold; Cresyl violet

MeSH Terms

Adult
Animals
Axotomy
Benzoxazines
Frozen Sections
Humans
Male
Peripheral Nerve Injuries
Peripheral Nerves
Peroneal Nerve
Rats
Rats, Sprague-Dawley
Sciatic Nerve
Spinal Nerves
Sutures
Tibial Nerve
Viola
Benzoxazines