Post-Stroke Neurological Impairments in Rats with Functional Asymmetry of the Cerebral Hemispheres

Rats with a model of ischemic stroke in the sensorimotor zone of the cortex induced by removal of a fragment of the meninges with their superficial vessels were used to study the effects of the location of focal ischemia in the left and right hemispheres on the severity of neurological deficit. Preliminary testing for food grasping with the forelimb was used to identify the dominant hemisphere, i.e., right-handed and left-handed rats. The functions of the forelimbs were monitored daily for eight weeks in a cylinder test, and a whiskers test and swimming test were also performed. There were no differences in measures on these tests in rats with strokes in the right and left hemispheres throughout the study. In rats with lesions in the dominant hemisphere, recovery of forelimb functions was significantly better than in those with lesions in the non-dominant hemisphere. The link between brain lateralization in rats and the level of recovery of motor function should be taken into account when planning the design of preclinical studies of new agents for the treatment of stroke.