STRIATAL DOPAMINE-MEDIATED MOTOR BEHAVIOR IS ALTERED FOLLOWING OCCLUSION OF THE MIDDLE CEREBRAL-ARTERY

Cerebral infarct (stroke) causes striatal damage with subsequent deterioration of sensorimotor and cognitive functions that may be mediated by the dopamine receptor system. In the present study, transient, focal ischemia was induced in Sprague-Dawley rats by middle cerebral artery occlusion. Ischemic animals exhibited significantly less dopamine antagonist (haloperidol)-induced catalepsy and more dopamine agonist (amphetamine)-induced hyperactivity than sham-operated animals. Younger ischemic animals showed more profound behavioral alteration but also displayed greater recovery over time than older ischemic animals. Histologic data revealed a lateral striatal lesion in all ischemic animals. These results place the striatal dopaminergic system as a possible strategic venue for the treatment of cerebral ischemia. In addition, aging is found to be a risk factor for stroke as noted in humans.