Application of TreadScan Gait Analysis System in the Evaluation of Rat Spinal Cord Contusion Model

Objective: To assess the utility of TreadScan gait analysis system in evaluating rat spinal cord contusion model. Methods: Rat spinal cord contusion model was established by a BenchmarkTM stereotaxic cortical impactor which was connected to PinPointTM precision contact sensor. Image J image analysis software was used to measure the initial lesion volume of injured epicenter and adjacent area at posttraumatic 30 min. TreadScan gait analysis system was applied to describe the behavioral characteristics of the rats at preoperative and posttraumatic 7, 14, 21, 28 d. Morphological changes were inspected by using the Harris' s HE staining in combination with Luxol fast blue staining technique at posttraumatic 1, 7, 14, 28 d. Results: The initial lesion volume of spinal cord in model group was(4.17±0.15) mm3(x±s, n=5) with a range of 4.02 to 4.32 mm3 and fitted to the normal distribution. As compared to the preoperative, there were significant differences(P0.05) in each behavior parameters of the postoperative in model group. As compared to the sham group, the Average Print Area, Stride Length, Inst Run Speed and Regularity Index were decreased significantly in model group(P0.05). However, the Stride Time, Swing Time, Rear Track Width, Minimum Longitudinal Deviation were significantly increased(P0.05). In addition to the injured epicenter, the morphology of adjacent region tissue was basically intact at posttraumatic 1 d. However, overtime the severity of tissue degeneration and demyelination in model group were significantly higher than those in sham group, with the trend of spreading to the surrounding areas. Conclusion: The rat spinal cord contusion model prepared by a BenchmarkTM stereotaxic cortical impactor has a good replicability. TreadScan gait analysis system was particularly objective and accurate in evaluating the behavioral characteristics after SCI in rats.