Limits...
A consistent, quantifiable, and graded rat lumbosacral spinal cord injury model.

Wen J, Sun D, Tan J, Young W - J. Neurotrauma (2015)

Bottom Line: The result shows that peroneal and tibial motoneurons were respectively distributed in 4.71 mm and 5.01 mm columns in the spinal cord.Dropping a 10-g weight from 25 mm or 50 mm caused 1.5 mm or 3.75 mm gaps in peroneal and tibial motoneuronal columns, respectively, and increased spinal cord white matter loss.Fifty millimeter contusions significantly increased FL and reduced TS, ITS, STS, SITS, SFI, and SSI more than 25 mm contusions, and resulted in smaller axon and myelinated axon diameters in tibial and peroneal nerves and greater atrophy of gastrocnemius and anterior tibialis muscles, than 25 mm contusions.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey.

ABSTRACT
The purpose of this study is to develop a rat lumbosacral spinal cord injury (SCI) model that causes consistent motoneuronal loss and behavior deficits. Most SCI models focus on the thoracic or cervical spinal cord. Lumbosacral SCI accounts for about one third of human SCI but no standardized lumbosacral model is available for evaluating therapies. Twenty-six adult female Sprague-Dawley rats were randomized to three groups: sham (n=9), 25 mm (n=8), and 50 mm (n=9). Sham rats had laminectomy only, while 25 mm and 50 mm rats were injured by dropping a 10 g rod from a height of 25 mm or 50 mm, respectively, onto the L4-5 spinal cord at the T13/L1 vertebral junction. We measured footprint length (FL), toe spreading (TS), intermediate toe spreading (ITS), and sciatic function index (SFI) from walking footprints, and static toe spreading (STS), static intermediate toe spreading (SITS), and static sciatic index (SSI) from standing footprints. At six weeks, we assessed neuronal and white matter loss, quantified axons, diameter, and myelin thickness in the peroneal and tibial nerves, and measured cross-sectional areas of tibialis anterior and gastrocnemius muscle fibers. The result shows that peroneal and tibial motoneurons were respectively distributed in 4.71 mm and 5.01 mm columns in the spinal cord. Dropping a 10-g weight from 25 mm or 50 mm caused 1.5 mm or 3.75 mm gaps in peroneal and tibial motoneuronal columns, respectively, and increased spinal cord white matter loss. Fifty millimeter contusions significantly increased FL and reduced TS, ITS, STS, SITS, SFI, and SSI more than 25 mm contusions, and resulted in smaller axon and myelinated axon diameters in tibial and peroneal nerves and greater atrophy of gastrocnemius and anterior tibialis muscles, than 25 mm contusions. This model of lumbosacral SCI produces consistent and graded loss of white matter, motoneuronal loss, peripheral nerve axonal changes, and anterior tibialis and gastrocnemius muscles atrophy in rats.

No MeSH data available.


Related in: MedlinePlus

Retrograde labeling of tibial and common peroneal nerve, and anatomy of rat's spine and spinal cord. (A) Anatomy of rat's spine and spinal cord, exposed by a L1 laminectomy. (B) Enlarged box area in A. The lower margin of T13 laminae is indicated by a dashed line. (C) Motoneurons labeled by fluororuby (red) and fluorogold (blue) backfilled respectively from the tibial nerve and common peroneal nerve by retrograde labeling. The spinal cord cut between T13 and L1. R13, rib 13; T13, vertebra T13; L1, L1 vertebra; L2, L2 vertebra. Scale bar, 500 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4492780&req=5

f1: Retrograde labeling of tibial and common peroneal nerve, and anatomy of rat's spine and spinal cord. (A) Anatomy of rat's spine and spinal cord, exposed by a L1 laminectomy. (B) Enlarged box area in A. The lower margin of T13 laminae is indicated by a dashed line. (C) Motoneurons labeled by fluororuby (red) and fluorogold (blue) backfilled respectively from the tibial nerve and common peroneal nerve by retrograde labeling. The spinal cord cut between T13 and L1. R13, rib 13; T13, vertebra T13; L1, L1 vertebra; L2, L2 vertebra. Scale bar, 500 μm.

Mentions: We used three GFP Sprague-Dawley rats to identify locations of tibial and common peroneal motoneuron pools (GFP Sprague-Dawley rats express green fluorescent protein so that the sections were fluorescent green). We backfilled tibial and common peroneal nerves with Fluoro-Gold (blue fluorescence) and Fluoro-Ruby (reddish orange fluorescence). To expose the T13-L1 junction, we did a laminectomy of L1 (Fig. 1A), marked the lower edge of T13 (indicated by dashed line in Fig. 1B) with a suture at the laminectomy edge, cut the spinal cord with a sharp scalpel, and then removed the lamina of T13. Figure 1 shows a horizontal section of the spinal cord with a cut at the lower edge of T13.


A consistent, quantifiable, and graded rat lumbosacral spinal cord injury model.

Wen J, Sun D, Tan J, Young W - J. Neurotrauma (2015)

Retrograde labeling of tibial and common peroneal nerve, and anatomy of rat's spine and spinal cord. (A) Anatomy of rat's spine and spinal cord, exposed by a L1 laminectomy. (B) Enlarged box area in A. The lower margin of T13 laminae is indicated by a dashed line. (C) Motoneurons labeled by fluororuby (red) and fluorogold (blue) backfilled respectively from the tibial nerve and common peroneal nerve by retrograde labeling. The spinal cord cut between T13 and L1. R13, rib 13; T13, vertebra T13; L1, L1 vertebra; L2, L2 vertebra. Scale bar, 500 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4492780&req=5

f1: Retrograde labeling of tibial and common peroneal nerve, and anatomy of rat's spine and spinal cord. (A) Anatomy of rat's spine and spinal cord, exposed by a L1 laminectomy. (B) Enlarged box area in A. The lower margin of T13 laminae is indicated by a dashed line. (C) Motoneurons labeled by fluororuby (red) and fluorogold (blue) backfilled respectively from the tibial nerve and common peroneal nerve by retrograde labeling. The spinal cord cut between T13 and L1. R13, rib 13; T13, vertebra T13; L1, L1 vertebra; L2, L2 vertebra. Scale bar, 500 μm.
Mentions: We used three GFP Sprague-Dawley rats to identify locations of tibial and common peroneal motoneuron pools (GFP Sprague-Dawley rats express green fluorescent protein so that the sections were fluorescent green). We backfilled tibial and common peroneal nerves with Fluoro-Gold (blue fluorescence) and Fluoro-Ruby (reddish orange fluorescence). To expose the T13-L1 junction, we did a laminectomy of L1 (Fig. 1A), marked the lower edge of T13 (indicated by dashed line in Fig. 1B) with a suture at the laminectomy edge, cut the spinal cord with a sharp scalpel, and then removed the lamina of T13. Figure 1 shows a horizontal section of the spinal cord with a cut at the lower edge of T13.

Bottom Line: The result shows that peroneal and tibial motoneurons were respectively distributed in 4.71 mm and 5.01 mm columns in the spinal cord.Dropping a 10-g weight from 25 mm or 50 mm caused 1.5 mm or 3.75 mm gaps in peroneal and tibial motoneuronal columns, respectively, and increased spinal cord white matter loss.Fifty millimeter contusions significantly increased FL and reduced TS, ITS, STS, SITS, SFI, and SSI more than 25 mm contusions, and resulted in smaller axon and myelinated axon diameters in tibial and peroneal nerves and greater atrophy of gastrocnemius and anterior tibialis muscles, than 25 mm contusions.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey.

ABSTRACT
The purpose of this study is to develop a rat lumbosacral spinal cord injury (SCI) model that causes consistent motoneuronal loss and behavior deficits. Most SCI models focus on the thoracic or cervical spinal cord. Lumbosacral SCI accounts for about one third of human SCI but no standardized lumbosacral model is available for evaluating therapies. Twenty-six adult female Sprague-Dawley rats were randomized to three groups: sham (n=9), 25 mm (n=8), and 50 mm (n=9). Sham rats had laminectomy only, while 25 mm and 50 mm rats were injured by dropping a 10 g rod from a height of 25 mm or 50 mm, respectively, onto the L4-5 spinal cord at the T13/L1 vertebral junction. We measured footprint length (FL), toe spreading (TS), intermediate toe spreading (ITS), and sciatic function index (SFI) from walking footprints, and static toe spreading (STS), static intermediate toe spreading (SITS), and static sciatic index (SSI) from standing footprints. At six weeks, we assessed neuronal and white matter loss, quantified axons, diameter, and myelin thickness in the peroneal and tibial nerves, and measured cross-sectional areas of tibialis anterior and gastrocnemius muscle fibers. The result shows that peroneal and tibial motoneurons were respectively distributed in 4.71 mm and 5.01 mm columns in the spinal cord. Dropping a 10-g weight from 25 mm or 50 mm caused 1.5 mm or 3.75 mm gaps in peroneal and tibial motoneuronal columns, respectively, and increased spinal cord white matter loss. Fifty millimeter contusions significantly increased FL and reduced TS, ITS, STS, SITS, SFI, and SSI more than 25 mm contusions, and resulted in smaller axon and myelinated axon diameters in tibial and peroneal nerves and greater atrophy of gastrocnemius and anterior tibialis muscles, than 25 mm contusions. This model of lumbosacral SCI produces consistent and graded loss of white matter, motoneuronal loss, peripheral nerve axonal changes, and anterior tibialis and gastrocnemius muscles atrophy in rats.

No MeSH data available.


Related in: MedlinePlus