RATS: An Alternative Solution for Tracking Open Field Locomotion of Rats with Spinal Cord Injury

Changes in locomotion for animals under various health conditions including spinal cord injuries (SCI) provide insights on the disease and its recovery process. This can be achieved by analyzing their behavior in an open field test (OFT). Existing systems for OFT study are expensive and lack customization options, making it unsuitable for research projects with limited means. This study introduces Rodent Activity Tracking System (RATS), a new OFT system with automatic tracking and analysis to objectively assess the behavior of rats with SCI in comparison to healthy rats, focusing on distance traveled in the arena. 13 adults female Wistar rats were randomly divided into two groups – uninjured (7) and injured (6). For the injured group, contusion SCI was introduced on their T9/T10 thoracic area of the spinal cord using NYU Impactor device. The reliability of the newly developed system was compared with manual measurement, achieving a Cronbach’s alpha of 0.9979 for internal consistency. The accuracy of the distance measured by the system showed no significant difference compared to the manual method, with an intraclass correlation coefficient (ICC) of 0.9909 and a Pearson correlation, r, of 0.9924. Bland-Altman analysis portrayed similar results with most measurements falling within 95% range. RATS demonstrates its capability by successfully measuring the average distance traveled by the rats, with the healthy rats covering on average 70% more distance than SCI-injured rats. This suggests that RATS is a reliable and valid tool for measuring the locomotor behavior of rats in OFT.