title: Excitatory effects of 5-hydroxytryptamine on the medial vestibular nuclear neuron via the 5-HT2 receptor.
abstract: This study was designed to investigate the mechanisms of action of the 5-HT2 receptor on the spontaneous electrical activity and potassium currents of the rat medial vestibular nuclear neurons using whole-cell patch clamp recordings. The spike width of spontaneous action potential was not affected by 5-alpha-methylhydroxytryptamine. The spike frequency and resting membrane potential was increased by 5-alpha-methylhydroxytryptamine. The amplitude of afterhyperpolarization was decreased by 5-alpha-methylhydroxy-tryptamine. The peak current of the potassium currents of the neuron treated with 5-alpha-methylhydroxytryptamine was decreased. After blockade of calcium-dependent potassium currents, 5-alpha-methylhydroxytryptamine did not inhibit potassium currents. These results suggest 5-alpha-methylhydroxytryptamine increases spontaneous firing of the medial vestibular nuclear neurons by inhibiting calcium dependent potassium currents.
authors.affiliation: Department of Physiology, Chonnam National University Medical School, Gwaugju, Korea.
authors.forename: Han-Seong
authors.initials: HS
authors.lastname: Jeong
authors.forename: Young Chai
authors.initials: YC
authors.lastname: Lim
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Kim
authors.forename: Tag
authors.initials: T
authors.lastname: Heo
authors.forename: Seung-Mun
authors.initials: SM
authors.lastname: Jung
authors.forename: Yong Bum
authors.initials: YB
authors.lastname: Cho
authors.forename: Jae Yeoul
authors.initials: JY
authors.lastname: Jun
authors.forename: Jong-Seong
authors.initials: JS
authors.lastname: Park
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004533:Egtazic Acid / Q000494:pharmacology; D004594:Electrophysiology; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology*; D014726:Vestibular Nuclei / Q000166:cytology* / Q000187:drug effects*
chemical_list: D015221:Potassium Channels; D011985:Receptors, Serotonin; D012701:Serotonin; D004533:Egtazic Acid