Effects of Environmental Reinforcement Through Motivation on Motor and Cognitive Function in Rats With Focal Ischemic Brain Injury

1) It is known that individual factors as cognitive, perception, emotion, and motivation may greatly influence on recovery from neurologic region. This study was to investigate the effects of environmental reinforcement through motivation to perform the tasks voluntarily on motor and cognition function in rats with focal ischemic brain injury. Focal ischemic brain injury was induced in Sprague-Dawley rats (15 rats, 250±50 g) through middle cerebral artery occlusion (MCAo). And then, experiment groups were randomly divided into three groups; The control group: MCAo induction (n1=5), the environmental reinforcement (ER) group: the application for ER after MCAo induction (n2=5), the environmental reinforcement through motivation (ERM) group: the application for ERM after MCAo induction (n3=5). The climbing test (CT) and the modified limb placing tests (MLPTs) to measure the motor function and the Morris water maze acquisition test (MWMAT) and the Morris water maze retention test (MWMRT) to measure the cognitive function were performed. For the CT, the ERM group was significantly larger than the ER group. For the MLPTs, the ERM group was significantly decreased compared to other groups. For the MWMAT, the time to find the circular platform in the ERM group significantly decreased compared to other groups. For the MWMRT, the time to dwell on the quadrant circular platform in the ERM group was significantly increased compared to other groups. These results suggested that the ERM could improve the motor and cognitive functions in the rats with focal ischemic brain injury.