Using an Automated Skilled Reaching Task to Investigate Predictors of Motor Impairment and Recovery Following Photothrombotic Stroke

Abstract

Accurate assessment of sensorimotor function in rodent models of stroke is essential for understanding how brain reorganization or plasticity contribute to functional recovery. We recently developed the Home-cage Automated Skilled Reaching Apparatus (HASRA) that allows automated training and assessment of mice engaged in a skilled reaching task. To validate the HASRA as a sensitive tool for assessing post-stroke performance, group-housed mice were trained on the reaching task for 14-21 days, followed by an M1 photothrombotic stroke or sham procedure, after which performance was monitored for 4 weeks. Performance at baseline, acutely, and at endpoint was compared. Stroke mice had a significantly reduced performance acutely compared to baseline but improved by endpoint. The stroke group was divided into two sub-groups: 1) high endpoint success and 2) low endpoint success groups. We found that training success, acute success, and learning rate were significant predictors of endpoint success. Furthermore, using a novel semi-automated lesion localization workflow, we were able to find that the percentage of damage in the secondary motor area was also a predictor of endpoint performance. Overall, using automated tools like the HASRA for the quantification of poststroke motor impairments and semi-automated tools for the quantification of lesion location are essential for investigating potential predictors of stroke recovery and designing effective therapies.