Development of a chronic compression spinal cord injury model in neonatal and adult rats

Background: Spinal cord injury presents a significant burden globally, with traumatic spinal cord injury being the predominant cause historically. However, nontraumatic spinal cord injury (NTSCI) is emerging as a significant contributor, particularly in devel-oped nations, yet it remains poorly understood due to underreporting and misclassifi-cation. NTSCI, spanning various etiologies such as bony growths, vascular conditions, infections, neoplastic conditions, and immune disorders, poses unique challenges in diagnosis and treatment, often resulting in lifelong morbidity. This study addresses the lack of suitable animal models for NTSCI research, especially in neonatal animals. Methods: Utilizing a solid spacer approach, we developed a compression NTSCI model applicable to both neonatal and adult Sprague-Dawley rats. Results: Through anatomical measurements and in vivo experiments, we confirmed the feasibility and safety of the spacer insertion procedure and observed no acute off- target effects. Conclusion: The versatility of this model lies in its adaptability to different ages of rats, offering a cost-effective and reproducible means to induce graded injuries. Moreover, behavioral assessments demonstrated observable hindlimb function, validating the model's utility for studying functional outcomes. Although challenges persist, par-ticularly in accounting for spinal column growth in neonatal animals, this model fills a crucial gap in pediatric NTSCI research. By providing a platform to investigate patho-physiological mechanisms and test potential treatments, it offers promising avenues for advancing our understanding and management of pediatric NTSCI