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

Area of Science:

• Neuroscience
• Spinal Cord Injury Research
• Animal Models

Background:

• Lumbosacral spinal cord injuries (SCI) account for a significant portion of human SCI cases.
• A standardized animal model for lumbosacral SCI is lacking for therapy evaluation.
• Existing SCI models predominantly focus on thoracic or cervical regions.

Purpose of the Study:

• To develop a reproducible rat model of lumbosacral spinal cord injury (SCI).
• To induce consistent motoneuronal loss and behavioral deficits in rats.
• To establish a standardized model for evaluating therapeutic interventions for lumbosacral SCI.

Main Methods:

• Twenty-six Sprague-Dawley rats were divided into sham, 25 mm, and 50 mm contusion groups.
• Lumbosacral spinal cord (L4-5) was injured using a 10g rod dropped from controlled heights.
• Functional deficits were assessed using gait analysis (footprint parameters) and electrophysiology.

Main Results:

• The 50 mm contusion caused significantly greater motoneuronal loss and white matter damage than the 25 mm contusion.
• Behavioral deficits, including altered footprint length and reduced toe spreading, were dose-dependent.
• Peripheral nerve changes and muscle atrophy in the tibialis anterior and gastrocnemius were observed, correlating with injury severity.

Conclusions:

• The developed rat lumbosacral SCI model consistently produces graded motoneuronal and white matter loss.
• This model accurately reflects behavioral deficits and peripheral nerve/muscle changes seen in human lumbosacral SCI.
• It serves as a valuable tool for preclinical assessment of therapies targeting lumbosacral SCI.