Expression of Phosphorylated ERK1/2 and cFos Proteins in Vestibular Nuclei by Selective Stimulation of Horizontal Semicircular Canal

J Korean Neurol Assoc > Volume 23(2); 2005 > Article

Journal of the Korean Neurological Association 2005;23(2): 257-263.

전정신경핵에서 수평 반규관의 선택적 자극에 의한 pERK1/2와 cFos 단백 발현

최봉기, 이영주 이학승 박성욱 박현영 장 혁 김요식 조광호 최명애* 이재효* 김민선* 박병림

원광대학교 의과대학 신경과학교실, 생리학교실

Expression of Phosphorylated ERK1/2 and cFos Proteins in Vestibular Nuclei by Selective Stimulation of Horizontal Semicircular Canal

Bong-Ki Choi

Department of Neurology and Physiology*, Wonkwang University School of Medicine, Iksan, Korea

Abstract

Background: There is a little information about the effect of selective vestibular stimulation on the expression of activity-dependent metabolic markers in the vestibular nuclei. The purpose of this study was to evaluate effect of afferent excitation of the horizontal semicircular canal on expression of phosphorylated ERK1/2 (pERK1/2) and cFos proteins in the vestibular nuclei.
Methods: The horizontal semicircular canal of Sprague-Dawley rats was selectively stimulated by using the sinusoidal horizontal stimulator with 10-minute duration of stimulation. Conventional immunohistochemical method was used to visualize pERK1/2 or cFos immunoreactive neurons in the vestibular nuclei following rotation.
Results: Five minutes after stimulation of the horizontal semicircular canal there was a high expression of pERK1/2 protein in the medial vestibular nucleus among 4 major subnuclei of the central vestibular nuclear complex. On the contrary, immunoreactivity of cFos protein was observed in the medial and inferior vestibular nucleus 2 hours after horizontal sinusoidal rotation. The lateral vestibular nucleus was free from the expression of pERK1/2 and cFos proteins in response to excitation of the horizontal semicircular canal. However, in the vestibular nuclei of unilaterally labyrinthectomized rats expression of pERK and cFos proteins was markedly suppressed in ipsi-lesional side as well as contra-lesional side following stimulation of the horizontal semicircular canal. Furthermore no expression of pERK1/2 and cFos protein in the bilateral vestibular nuclei of bilaterally labyrinthectomized rats was noted after stimulation of the horizontal semicircular canal.
Conclusions: Therefore these results of present study suggest that excitatory afferent signals from the peripheral vestibular receptors are essential for protein translation for pERK1/2 and cFos in response to stimulation of the semicircular canal. KeyWords:Phosphorylated ERK1/2 (pERK1/2), cFos, Horizontal semicircular canal