title: Vulnerability of the vestibular organs to transient ischemia: implications for isolated vascular vertigo.
abstract: The aim of this study was to elucidate the mechanism of isolated vascular vertigo by determining selective and relative ischemic vulnerability of the vestibular structures using a global hypoperfusion model in rats. Sprague-Dawley male rats weighing 330-350 g were subjected to transient global ischemia of the brain using a 4-vessel-occlusion (4VO) model. After permanent occlusion of both vertebral arteries (VA) using electrocauterization, both common carotid arteries (CCAs) were occluded for 5-20 min with ligation. One hour after reperfusion of the CCAs, the animals were sacrificed and subjected to c-Fos staining of the entire cerebellum, brainstem, and vestibular ganglion. The rats in the sham group received the same surgical procedures except the vessel ligation. With 4VO for 5-15 min, both the sham and experimental groups showed a weak and scarce c-Fos expression in the medial vestibular nucleus (MVN), neuron Y, and cochlear nucleus. After 4VO for 20 min, only the MVN began to show a significant difference in the number of c-Fos positive neurons between the experimental and sham groups (33.7±17.7 vs.7.1±5.1, Wilcoxon rank test, p=0.005). With 4VO for up to 20 min, c-Fos positive neurons were not found in other areas of the brainstem and cerebellum, including the superior, lateral, and spinal vestibular nuclei, the vestibular ganglion, the cerebellar cortex, and the deep cerebellar nuclei. The vestibular structures appear to be vulnerable to ischemia more than any other structures in the brainstem and cerebellum. Of the vestibular structures, the MVN is most vulnerable to ischemic insults in rats. These findings are consistent with the common findings of vertigo as an initial and isolated symptom of posterior circulation ischemia in human.
authors.affiliation: Biomedical Research Institute, Seoul National University Bundang Hospital, Republic of Korea.
authors.forename: Jin Ok
authors.initials: JO
authors.lastname: Lee
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Park
authors.affiliation: Biomedical Research Institute, Seoul National University Bundang Hospital, Republic of Korea.
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Physiology, Wonkwang University School of Medicine and Brain Research Institute at Wonkwang University, Iksan, Republic of Korea.
authors.forename: Min Sun
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Physiology, Wonkwang University School of Medicine and Brain Research Institute at Wonkwang University, Iksan, Republic of Korea.
authors.forename: Byung Rim
authors.initials: BR
authors.lastname: Park
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea. Electronic address: jisookim@snu.ac.kr.
authors.forename: Ji-Soo
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000818:Animals; D001933:Brain Stem / Q000378:metabolism / Q000473:pathology*; D002531:Cerebellum / Q000378:metabolism / Q000473:pathology; D017626:Cochlear Nucleus / Q000378:metabolism / Q000473:pathology; D017950:Ganglia, Sensory / Q000378:metabolism / Q000473:pathology; D002546:Ischemic Attack, Transient / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009474:Neurons / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D014717:Vertigo / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D014726:Vestibular Nuclei / Q000378:metabolism / Q000473:pathology; D014722:Vestibule, Labyrinth / Q000294:innervation / Q000378:metabolism / Q000473:pathology*
chemical_list: D016760:Proto-Oncogene Proteins c-fos
keywords: Ischemia; Rat; Vertigo; Vestibular nucleus