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Updated: May 10, 2026
A Minimally Invasive, Fast Spinal Cord Lateral Hemisection Technique for Modeling Open Spinal Cord Injuries in Rats
Published on: March 23, 2022
Optimal time window of myelotomy in rats with acute traumatic spinal cord injury: a preliminary study
1School of Rehabilitation Medicine of Capital Medical University, Department of Spinal and Neural Function Reconstruction, China Rehabilitation Research Center, Beijing, People's Republic of China.
Objectives:
Pathophysiological mechanisms underlying spinal cord injury (SCI) partially involve edema and formation of a hematoma. Myelotomy seems to be a promising intervention. However, the appropriate timing of myelotomy is still unknown in SCI. Here we aimed to determine the timing of microsurgical myelotomy in an animal model of SCI.
Methods:
The SCI model was contusion-induced with a new york university impactor. Sixty-five adult female rats were randomly divided into the following groups: laminectomy alone (the 'sham group', SG), laminectomy plus contusion (the 'contusion group', CG) or laminectomy plus contusion followed by myelotomy at 8, 24 or 48 h (8 h-MTG [myelotomy-treated group], 24 h-MTG or 48 h-MTG). Functional recovery was evaluated via the open field test and the inclined plane test every week after SCI. The percentage of spared white matter area (SWMA) and ultrastructure characteristics of the injured dorsolateral spinal cord were determined on the 42nd day after SCI.
Results:
Compared with the CG, myelotomy at 8 h-MTG or 24 h-MTG greatly improved the BASSO-BEATTIE- BRESNAHAN scores (P<0.008), whereas the 48 h-MTG showed less efficacy (P=0.023). All myelotomy groups showed higher mean angle values in an inclined plane test (P<0.005) and had greater percentages of SWMA than the CG. Rats in the 24 h-MTG showed a higher intra-axonal fraction and myelin fraction than those in 48 h-MTG (P<0.005).
Conclusion:
Myelotomy up to 48 h after SCI improves recovery in rats. The potential time window of myelotomy may be between 8 and 24 h after SCI.
Insights
Microsurgical myelotomy improves spinal cord injury recovery in rats, with optimal timing between 8 and 24 hours post-injury. Early intervention enhances functional outcomes and preserves white matter.
Area of Science:
- Neuroscience
- Neurosurgery
- Regenerative Medicine
Background:
- Spinal cord injury (SCI) involves edema and hematoma formation, hindering recovery.
- Myelotomy is a potential intervention for SCI, but optimal timing remains unclear.
- Understanding the therapeutic window for myelotomy is crucial for improving SCI outcomes.
Purpose of the Study:
- To determine the optimal timing for microsurgical myelotomy in a rat model of spinal cord injury.
- To evaluate the impact of different myelotomy timings on functional recovery and histological outcomes.
Main Methods:
- A contusion-induced SCI model was established in 65 female rats.
- Rats were assigned to sham, contusion, or myelotomy groups (8, 24, or 48 hours post-injury).
- Functional recovery was assessed using open field and inclined plane tests; white matter sparing and ultrastructure were analyzed.
Main Results:
- Myelotomy at 8 or 24 hours significantly improved functional recovery scores compared to the contusion group.
- All myelotomy groups exhibited increased spared white matter area and improved inclined plane test performance.
- The 24-hour myelotomy group showed superior intra-axonal and myelin fractions compared to the 48-hour group.
Conclusions:
- Microsurgical myelotomy up to 48 hours after SCI can improve recovery in rats.
- The optimal therapeutic window for myelotomy appears to be between 8 and 24 hours post-SCI.
- Early myelotomy enhances both functional recovery and histological preservation after spinal cord injury.
