Abstract

The purpose of this study was to evaluate expression of immediate-early gene products, metabolic marker of neural excitation in neuronal cells, in the vestibular nuclear complex by occlusion of anterior cerebellar artery(AICA) in adult Sprague-Dalwey rats. After chloral hydrate anesthesia all animals were received unilateral occlusion of AICA by using microsurgical clamp for 30 min to induce temporally ischemia in brain stem and inner ear. Immunohistochemical staining and image analysis for cFos, FosB, Krox-24, and JunB proteins were performed 2 hours after occlusion of AICA. There was high expression of cFos protein in bilateral medial medial and inferior vestibular nuclei 2 hours after unilateral occlusion of anterior cerebellar artery(AICA). But AICA occlusion induced minimal change in cFos expression in lateral and superior vestibular nuclei. Mild to moderate expression of FosB and Jun B protein was observed 2 hour ischemic injury in brain stem and inner ear. A few neurons in vestibular complex showed immunoreactivity for Krox-24 protein following AICA occlusion. Furthermore pretreatment of bilateral labyrinthectomy resulted in significant reduction of immunoreactivity for cFos, FosB, and JunB proteins in medial and vesitbular expressions 2 hours after unilateral occlusion of AICA. These results suggest that ischemia of peripheral vestibular apparatus play a major role in expression of immediate-early gene products in medial and inferior vestibular nuclei of rats.