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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 spared motoneurons. (A–C) are exemplary images of contused spinal cords at T13/L1 from the Sham, 25 mm and 50 mm injury groups, respectively. (D–F) are camera lucida drawings corresponding to A-C, indicating counted motoneurons. Scale bar (A-F), 500 μm. (G) shows a graph of the number of counted spared motoneurons back-labeled from the tibial and peroneal nerves in the Sham (n=4), 25 mm (n=4), and 50 mm (n=4) injury groups. The error bars (D) indicate standard deviation. * indicates p<0.05 versus the Sham group, # indicates p<0.05 versus the 25 mm group.
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f5: Retrograde labeling of spared motoneurons. (A–C) are exemplary images of contused spinal cords at T13/L1 from the Sham, 25 mm and 50 mm injury groups, respectively. (D–F) are camera lucida drawings corresponding to A-C, indicating counted motoneurons. Scale bar (A-F), 500 μm. (G) shows a graph of the number of counted spared motoneurons back-labeled from the tibial and peroneal nerves in the Sham (n=4), 25 mm (n=4), and 50 mm (n=4) injury groups. The error bars (D) indicate standard deviation. * indicates p<0.05 versus the Sham group, # indicates p<0.05 versus the 25 mm group.

Mentions: To identify loss of specific motoneuronal groups, we used Fluoro-Ruby (FR) and Fluoro-Gold (FG) to identify the tibial and peroneal motoneuron pools. FR usually produces a reddish fluorescence while FG tends to be bluish. Figure 5 shows FR and FG labeled motoneurons back-labeled from the tibial nerve and common peroneal nerve. Figure 5A to 5C are pictures with all motoneurons from one animal projected on one spinal cord background. Figure 5D to 5F are hand-drawn (camera lucida) pictures corresponding to Figure 5A to 5C. All labeled neurons were located in gray matter and exhibited morphology consistent with motoneurons. The cells have large multipolar perikarya with several dendrites that extended radially from the cell body.


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 spared motoneurons. (A–C) are exemplary images of contused spinal cords at T13/L1 from the Sham, 25 mm and 50 mm injury groups, respectively. (D–F) are camera lucida drawings corresponding to A-C, indicating counted motoneurons. Scale bar (A-F), 500 μm. (G) shows a graph of the number of counted spared motoneurons back-labeled from the tibial and peroneal nerves in the Sham (n=4), 25 mm (n=4), and 50 mm (n=4) injury groups. The error bars (D) indicate standard deviation. * indicates p<0.05 versus the Sham group, # indicates p<0.05 versus the 25 mm group.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: Retrograde labeling of spared motoneurons. (A–C) are exemplary images of contused spinal cords at T13/L1 from the Sham, 25 mm and 50 mm injury groups, respectively. (D–F) are camera lucida drawings corresponding to A-C, indicating counted motoneurons. Scale bar (A-F), 500 μm. (G) shows a graph of the number of counted spared motoneurons back-labeled from the tibial and peroneal nerves in the Sham (n=4), 25 mm (n=4), and 50 mm (n=4) injury groups. The error bars (D) indicate standard deviation. * indicates p<0.05 versus the Sham group, # indicates p<0.05 versus the 25 mm group.
Mentions: To identify loss of specific motoneuronal groups, we used Fluoro-Ruby (FR) and Fluoro-Gold (FG) to identify the tibial and peroneal motoneuron pools. FR usually produces a reddish fluorescence while FG tends to be bluish. Figure 5 shows FR and FG labeled motoneurons back-labeled from the tibial nerve and common peroneal nerve. Figure 5A to 5C are pictures with all motoneurons from one animal projected on one spinal cord background. Figure 5D to 5F are hand-drawn (camera lucida) pictures corresponding to Figure 5A to 5C. All labeled neurons were located in gray matter and exhibited morphology consistent with motoneurons. The cells have large multipolar perikarya with several dendrites that extended radially from the cell body.

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