Video tracking analysis system for forelimb akinesia test in the rat Parkinson model

Abstract

This study analyzes forelimb akinesia with stepping test in adult male rats with nigrostriatal cell loss and striatal dopamine depletions, similar to levels reported in the clinical setting of Parkinson Disease (PD), and determines if subjects who received a pharmacological induction with apomorphine exhibit more robust parkinsonian effects. With manual testing only one parameter (adjusting steps) is evaluated; the software presented increases the number of parameters as it estimates adjusting steps, stepping time, step length and initiation time. Manual and automated adjusting steps scores are correlated to show software validity. Adult male rats received infusions of 6-hydroxydopamine (6-OHDA) in left corpus striatum. Two months after lesion they were tested for forelimb akinesia using stepping test, before and after an apomorphine induction. Video tracking analysis system developed consists in two stages: 1) where animals performance is recorded and their trajectories are acquired and processed using open source software; and 2) wherein post processing methods are conducted to measure stepping test parameters. Based on these measurements, the program has the ability to make statistical analysis and present data in different formats, including matrixes and graphs. Results show high correlations between manual and automated adjusting steps scores. What is more, this computerized system decreases inter/intra operator errors due to direct observation and handling, expands the amount of parameters assessed, early and acutely detects those parameters and increases data acquisition speed and quality.