Stroke-prone rats exhibit prolonged behavioral deficits without increased brain injury: an indication of disrupted post-stroke brain recovery of function

Neurosci Lett. 2004 Jan 16;354(3):229-33. doi: 10.1016/j.neulet.2003.09.079.

Abstract

Stroke-prone rat strains exhibit an increased stroke risk and sensitivity, and reduced endogenous mechanisms of ischemic brain tolerance. This experiment provides a comparative, serial evaluation of neurological deficits and brain injury following middle cerebral artery occlusion/permanent focal stroke in this high-risk strain. Stroke-prone spontaneously hypertensive (SHR-SP), spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats were evaluated over 28 days using magnetic resonance imaging (MRI), histopathology, and neurobehavioral testing. T2- and diffusion weighted-MRI was performed after 1, 10 and 28 days to measure the degree of stroke-induced brain injury. Normotensive WKY rats receiving the same stroke and other SHR-SP rats receiving sham surgery were used for control comparisons. Functional deficits were scored after 1, 4, 11, 18 and 28 days. The degree of brain infarction/injury was practically identical in hypertensive and stroke-prone rats. WKY rats exhibited significantly smaller infarcts (P<0.05), with neurological function recovering quickly to normal by day 11 in this strain. Functional deficits persisted longer in hypertensive rats, with function recovering to normal by day 18 (P<0.05). Functional deficits in SHR-SP rats persisted the longest, and were observed even after 28 days (P<0.05). This increased and prolonged neurologic dysfunction exhibited by SHR-SP compared to SHR rats, while exhibiting practically identical degrees of brain injury/infarction, reflects the increased stroke risk and sensitivity of this strain and suggests a reduced SHR-SP brain plasticity following injury. Therefore, the stroke-prone rat provides an enhanced and prolonged functional deficit model that can be used to elucidate those mechanisms/novel targets critical to longitudinal neurobehavioral recovery post-stroke.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Behavior, Animal / physiology*
  • Brain
  • Brain Infarction / pathology
  • Brain Injuries / etiology
  • Brain Injuries / pathology
  • Brain Injuries / physiopathology*
  • Brain Mapping
  • Disease Models, Animal
  • Functional Laterality
  • Hypertension / etiology
  • Infarction, Middle Cerebral Artery / physiopathology*
  • Magnetic Resonance Imaging / methods
  • Male
  • Movement / physiology
  • Postural Balance / physiology
  • Prosencephalon / pathology
  • Prosencephalon / physiopathology
  • Psychomotor Performance / physiology
  • Rats
  • Rats, Inbred SHR
  • Rats, Inbred WKY
  • Recovery of Function*
  • Statistics, Nonparametric
  • Stroke / etiology
  • Stroke / pathology
  • Stroke / physiopathology*
  • Time Factors