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Updated: Jul 15, 2026
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Unilateral Pyramidotomy of the Corticospinal Tract in Rats for Assessment of Neuroplasticity-inducing Therapies
Published on: December 15, 2014
Bilateral dorsal funicular lesions alter sensorimotor behaviour in rats
Srikanth G Kanagal1, Gillian D Muir
1Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan Saskatoon, Canada SK S7N 5B4. sri.kanagal@usask.ca
Experimental Neurology
|April 25, 2007
Summary
This study on spinal cord injury models found that while ascending sensory pathways (ASP) alone cause temporary motor deficits, combined damage with the corticospinal tract (CST) leads to persistent impairments in skilled movements.
Area of Science:
- Neuroscience
- Spinal Cord Injury Research
- Motor Control
Background:
- Spinal cord injury (SCI) models often damage the corticospinal tract (CST), crucial for human motor function.
- In rats, CST damage in the dorsal funiculus is inseparable from sensory fiber injury, complicating deficit attribution.
- Distinguishing CST-specific deficits from sensory pathway damage is vital for effective SCI research.
Purpose of the Study:
- To differentiate functional deficits caused by ascending sensory pathway (ASP) damage from those resulting from combined ASP and CST damage in a rat model.
- To investigate the distinct and combined roles of ASP and CST in skilled forelimb reaching and overground locomotion.
- To evaluate the impact of these specific spinal cord lesions on motor behavior and biomechanics.
Main Methods:
- Created distinct rat groups: one with isolated ascending sensory pathway (ASP) axotomy, and another with combined ASP and corticospinal tract (ASP+CST) damage.
- Assessed motor function using skilled reaching tasks and horizontal ladder walking tests.
- Measured ground reaction forces (GRF) and limb contact patterns during overground locomotion to analyze biomechanical changes.
Main Results:
- Isolated ASP lesions caused transient reaching and ladder impairments, with persistent subtle forelimb deficits.
- Combined ASP+CST lesions resulted in sustained deficits in reaching success and ladder walking over 8 weeks.
- Both groups showed altered GRFs and limb timing post-surgery, but no significant differences were observed between the ASP and ASP+CST groups in locomotion.
Conclusions:
- Ascending sensory pathways and CST axons both contribute to skilled limb movements.
- Ascending sensory information plays a role in overground locomotion, whereas descending CST input appears less critical for this specific task.
- Sensitive behavioral analysis methods are crucial for revealing detailed functional changes after spinal cord injury.
