Intrinsic locomotor outcome in dorsal transection of rat spinal cord: predictive value of minimal incision depth

• Published in: Spinal cord 2006-10, Vol.44 (10), p.605-613
• Main Authors: Brechtel, K, Tura, A, Abdibzadeh, M, Hirsch, S, Conrad, S, Schwab, J M
• Format: Article
• Language: English
• Subjects: Anatomy; Animals; Behavior, Animal; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cerebrospinal fluid. Meninges. Spinal cord; Cerebrospinal fluid. Spinal cord. Spinal roots. Spinal nerves; Contusions - pathology; Disease Models, Animal; Human Physiology; Indoles; Injuries of the nervous system and the skull. Diseases due to physical agents; Locomotion - physiology; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurochemistry; Neurology; Neuropsychology; Neurosciences; Neurosurgery; original-article; Predictive Value of Tests; Rats; Rats, Inbred Lew; Recovery of Function; Regression Analysis; Spinal Cord Injuries - pathology; Spinal Cord Injuries - physiopathology; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Time Factors; Traumas. Diseases due to physical agents
• ISSN: 1362-4393; 1476-5624
• DOI: 10.1038/sj.sc.3101894

Study design: Experimental, prospective, blinded, animal study. Objectives: Subtotal transection models in rodents are widely used in spinal cord injury (SCI) research. In this model, we investigate the effect of the dorso-ventral incision depth (ID) of the spinal cord on functional locomotor outcome using the Basso, Beattie, Bresnahan (BBB) scale. We introduce the minimal incision depth (ID min ) and the average lesion depth (ID mean ) as reliable, fast and easily available predictive parameters for intrinsic locomotor function. Setting: Tuebingen, Germany. Methods: Dorsal over-hemisection at the level of T8 was performed in male Lewis rats. Functional outcome 4 weeks after SCI and histological analysis of the lesion were studied and correlated in 36 animals. Animals reaching weight support (BBB⩾9) were considered as having reached functional recovery. Data analysis was performed in linear (ordinary least squares; OLS) and nonlinear (logistic) regression models for correlation of histological parameters and functional outcome. Results: BBB scores revealed a strong correlation with ID mean and ID min , showing a higher value in predicting functional outcome for the latter parameter. Based on logistic regression analysis, animals with an ID min of 69% would have a 95% probability of reaching weight support. Conclusion: These results demonstrate that histological analysis is crucial when functional outcome parameters are used in the dorsal over-hemisection SCI model. A simple and feasible histological evaluation can reliably predict spontaneous functional locomotor recovery in dorsal transection models and could provide a simple tool to identify treatment effects of new experimental therapeutic approaches.