전정 신경핵 칼륨 전류에 미치는 5-Hydroxytryptamine의 영향

Abstract

Background and Objectives：This study was aimed to explore the effects of the 5-hydroxytryptamine (5-HT) on potasium curents in rat vestibular nuclear neurons. Materials and Method：Sprague-Dawley rats aged 14 to 16 days were anesthetized with ether and decapitated. After enzymatic digestion, the portion of medial vestibular nucleus neuron was removed by microscope and whole-cell membrane curents were recorded at room temperature by using standard patch-clamp techniques. Results：When cells were held at - 70 mV and depolarized from - 60 mV to + 40 mV in 10 mV increments, sustained outward potasium curents were evoked. The response of medial vestibular nuclear neurons to 5-HT was not uniform. The outward potasium curents were increased in 17 of 40 cells and decreased in 23 of 40 cells. 5-carboxamidotryptamine, 5-HT1 agonist increased the outward potassium currents of the medial vestibular nuclear cell. α-methyl-5-hydroxytryptamine, 5-HT2 agonist decreased the outward potasium curents of the medial vestibular nuclear cell. Conclusion：These results suggest that 5-HT affects the potassium currents of the cell with diferent effects acording to the receptor subtype on which it acts. (Korean J Otolaryngol 2003 ;46 :915-21)