RESUMEN
Characterization of functional outcome in animal stroke models is essential to improve preclinical drug screenings. Operant procedures showed promising results for the identification of long-lasting functional deficits. In particular, a suppression of lever-pressing in high ratio schedules has been consistently found in rodent models of ischemic stroke. In the present work, we attempted to replicate these isolated observations, by submitting C57Bl/6J mice to a progressive fixed-ratio schedule of reinforcement three weeks after MCAO or sham surgery. Results showed a significant lever-pressing impairment in the MCAO group. Motivational factors (longer post-reinforcement pause, lesser appeal for food rewards) seemed accountable for the deficit, while motor abilities appeared preserved. These findings resemble fatigue-like states experienced by stroke survivors and may be used as long-term measures of behavioral outcome following experimental stroke.