J Korean Neurol Assoc > Volume 21(3); 2003 > Article

Journal of the Korean Neurological Association 2003;21(3): 273-282.

"흰쥐 내측 전정신경핵 뉴론의 억제성 시냅스 전도에 대한 글루탐산염 대사성 수용체의 역할"

박현영 ,

원광대학교 의과대학 신경과학교실

"Roles of Metabotropic Glutamate Receptors in Inhibitory Synaptic Transmission in Rat Medial Vestibular Nucleus Neurons"

Hyun Young Park

Deparetment of Neurology, Wonkwang University, School of Medicine

Abstract

"Background: The medial vestibular nucleus (MVN) is involved in the reflex control of the head and eyes, and the recovery of vestibular function after vestibular lesions. This study was performed to investigate the characteristics of inhibitory postsynaptic currents (IPSC) and the roles of metabotropic glutamate receptors on inhibitory synaptic trans-missions.
Methods: Whole cell patch clamp recordings were carried out from MVN neurons in brainstem slice of neonatal rats. Result s: The frequency and amplitude of the IPSC were significantly reduced by GABAA a n t a g o n I s t bicuculline (20 μM) but were not affected by the glycine antagonist strychnine (1 μM). The baseline frequency, ampli-tude and decay time constant of spontaneous IPSC (sIPSC) were 4.9 ±1.8 Hz, 25.9 ±3.1 pA, 8.7 ±0.5 ms, respectively. Glutamate (1 mM) increased the frequency of sIPSC, but decreased that of the miniature IPSC (mIPSC) in MVN neu-rons. Such dual effects of glutamate were mimicked by group I, II metabotropic glutamate receptor (mGluR) agonist ACPD (20 μM). The specific mGluR 2, 3 agonist DCG-IV (3 μM) reduced mIPSC frequency, but did not increase sIPSC frequency. The mGluR 1, 5 agonist DHPG (100 μM) increased sIPSC and mIPSC frequency. C o n c l u s i o n s: These data suggest that the IPSC recorded from MVN neurons are mediated mainly by GABAA receptors and gluta-mate- induced modulations of inhibitory synaptic transmissions can influence the excitability of MVN neurons.Key Words: Medial vestibular nucleus, Inhibitory postsynaptic currents, Metabotropic glutamate receptor"