Quantification Analysis of Behavioral Changes after Sciatic Nerve Ligation in Rats

Measuring behavior changes in humans and animals is ongoing research in both bioscience and neuroscience, due to its applications in nerve injury recovery. Previous studies focused on the sciatic nerve and its recovery process because partial damage to this nerve leads to paralyzed symptoms of entire lower body parts. Rats have been successfully used as a model for neuropathic pain such as partial sciatic nerve injury. Numerous behavioral tests have been used to measure pain behavior and determine the extent of damage in animals with induced nerve injury. However, data collection using behavioral tests is highly time-consuming and costly, because of visual inspection-based tests, manual labor, and the need for complicated equipment. The real-time video data can be obtained in animals' natural environment e.g. own cage, without the need for interacting with the animal, which potentially can influence the test results. DeepLabCut provides easy methods for observing and recording animal behavior in diverse settings using video data. In this study, to examine the behavioral changes in rats after sciatic nerve ligation, we (i) recorded videos of 9 rats during the first and fifth day after surgery, (ii) used DeepLabCut to track the rat's positions throughout the videos, and (iii) calculated behavior indexes based on spatio-temporal patterns that measure the behavioral changes in rats. The results in this study confirm our assumption that there were significant changes in the behavior of rats with partial sciatic nerve injury. These findings motivate us to investigate physiological processes accompanied by the recovery, and implement real-time monitoring and analysis for measuring behavior changes in rats.