Expression of Immediate-Early Gene Proteins by Transient Occlusion of Anterior Inferior Cerebellar Artery in Vestibular Nuclei of Sprague-Dawley Rats

J Korean Neurol Assoc > Volume 22(4); 2004 > Article

Journal of the Korean Neurological Association 2004;22(4): 360-367.

흰쥐 전정신경핵에서 전하소뇌동맥의 일시적 폐쇄에 의한 급성초기유전자 단백의 발현

이한샘, 한형석 이승회 박성욱 박현영 장 혁 김요식 조광호 김민선 최명애 박병림

원광대학교 의과대학 신경과학교실, 생리학교실 전정와우센터

Expression of Immediate-Early Gene Proteins by Transient Occlusion of Anterior Inferior Cerebellar Artery in Vestibular Nuclei of Sprague-Dawley Rats

Han Sam Lee

Departments of Neurology, Physiology and Vestibulocochlear Research Center*, Wonkwang University College of Medicine, Iksan, Korea

Abstract

Background: Anterior cerebellar artery (AICA) occlusion results in vestibular dysfunctions because the AICA supplies the vestibular nuclei (VN) in the brain stem as well as the peripheral vestibular organs in the inner ear. The purpose of this study was to evaluate the expression of immediate-early gene products, a metabolic marker of neural excitation in neurons, by AICA occlusion in the VN of Sprague-Dawley rats.
Methods: After chloral hydrate anesthesia all animals were subjected to unilateral AICA occlusion by using a microsurgical clamp for 30 min to induce a transient ischemia. Unilateral labyrinthectomy was chemically undertaken to eliminate vestibular afferent activity. Immunohistochemical staining and image analysis for cFos, FosB, Krox-24, and JunB proteins were performed 2 hours after AICA occlusion.
Results: There was a high expression of cFos protein in the bilateral medial and inferior VN 2 hours after AICA occlusion. AICA occlusion induced minimal changes in cFos protein expression in the lateral and superior VN. Mild to moderate expressions of FosB and JunB protein in VN was observed 2 hours after ischemic injury of the brain stem and inner ear. On the contrary, the number of cFos and FosB immunoreactive neurons significantly decreased in the medial vestibular nucleus ipsilateral to the injured labyrinth 2 hours after AICA occlusion in the UL group.
Conclusions: These results suggest that ischemic afferent activity from the peripheral vestibular apparatus is essential for the expression of immediate-early gene products in the medial and inferior VN of rats following AICA occlusion. Key Words: Vestibular nucleus, cFos, Anterior inferior cerebellar artery, Ischemia, Labyrinthectomy