Spontaneously Hypertensive Rats Present Exacerbated Focal Stroke Behavioral Outcomes

Abstract

This study aimed to analyze the effects of systemic arterial hypertension (SAH) in a model of permanent ischemic stroke (focal ischemia due to thermocoagulation of pial vessels) on sensorimotor function (cylinder test and patch removal test), behavioral tasks (novelty habituation memory open field task) and cerebral infarct size in adult male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) for 42 days after the occurrence of a stroke. We observed that the stroke caused asymmetry in the front paws and delayed adhesive removal. These effects were spontaneously reduced in WKY rats, but not in SHR. Short- and long-term novelty habituation memories were abolished by stroke in WYK and SHR. On the 3rd day after stroke, the size of the focal cerebral infarct was the same in WKY and SHR. However, on the 7th day, the infarct size decreased in WKY rats, but not SHR. These results suggested that SAH impairment of sensorimotor recovery in rats subjected to cerebral ischemia could be related to augmented focal cerebral infarct size. Moreover, the behavioral tasks used in this study were unaffected by Systemic Arterial Hypertension. Our results highlight the need for animal models of comorbidities in stroke research.