Artikel
The CatWalk XT® gait analysis – a reliable behavioural assessment for severe thoracic spinal cord injury in rats
Die CatWalk XT®-Ganganalyse: Eine zuverlässige Verhaltensbeurteilung für schwere thorakale Rückenmarksverletzungen bei Ratten
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Veröffentlicht: | 25. Mai 2022 |
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Gliederung
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Objective: To achieve an objective and integrated assessment of locomotor function remains challenging in spinal cord injury (SCI) animal models. Therefore, we studied the consistency of the CatWalk XT® gait analysis in evaluating behavioral outcome in a clinically relevant thoracic SCI model in rats.
Methods: 13 Wistar rats were randomly assigned to either a T9 clip compression/contusion SCI (SCI group) or a sham laminectomy (Sham group). Locomotion recovery was assessed weekly using the BBB open field score and the CatWalk XT® gait analysis. The weight of the animals was continuously recorded, and the experiment was terminated six weeks after SCI. In fluorescence analysis of the spinal cords, the percentage of preserved spinal cord tissue, reactive gliosis (glial fibrillary acidic protein (GFAP)), and tissue scarring (chondroitin sulfate proteoglycan (CSPG)) were quantified. Pearson or Spearman correlation analyses were performed to study the correlation of animal weight, the BBB open field score, the percentage of preserved tissue, and the severity of gliosis and fibrosis with 20 major CatWalk XT® parameters (r values are presented).
Results: The compression/contusion injury caused a bilateral and significant hindlimb functional impairment in all CatWalk XT®parameters. Over the course of the experiment, a significant level of spontaneous recovery compared to the first postinjury time point was observed in most of the CatWalk XT® parameters and the BBB open field score. Histologically, the overall percentage of preserved tissue within +/- 1200 μm of the lesion epicenter was 80.50 ± 2.93%. Correlation analysis of the hindlimb CatWalk XT® parameters, including regularity index, stride length, print area, max contact area, and swing speed with the reactive gliosis (p = 0.048) and tissue scarring (p = 0.033) yielded significantly higher r values than the BBB score. Moreover, in the print parameters, such as maximum intensity or print area, using the ratio (hindlimb values divided by forelimb values) could significantly decrease the bias caused by the weight increase during the recovery, compared to using absolute values from hindlimb measurements (p < 0.001).
Conclusion: The CatWalk XT® system is an objective and consistent tool for assessing the impairment and recovery of locomotor function after thoracic contusion/compression SCI in rats, showing a good correlation with the BBB open field score, spinal cord tissue sparing, gliosis, and fibrosis.