Korean J Otolaryngol-Head Neck Surg.  2003 Nov;46(11):915-921.

Effects of 5-Hydroxytryptamine on Potassium Currents of the Medial Vestibular Nuclear Neuron in the Rat

• Jeong HS
• Cha SH
• Jang MJ
• Cho YB
• Jun JY
• Park JS

Abstract

BACKGROUND AND OBJECTIVES
This study was aimed to explore the effects of the 5-hydroxytryptamine (5-HT) on potassium currents 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 micropunching and gently agitated. The dissociated neurons were transferred into a recording chamber mounted on an inverted microscope and whole-cell membrane currents 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 potassium currents were evoked. The response of medial vestibular nuclear neurons to 5-HT was not uniform. The outward potassium currents 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. alpha-methyl-5-hydroxytryptamine, 5-HT2 agonist decreased the outward potassium currents of the medial vestibular nuclear cell. CONCLUSION: These results suggest that 5-HT affects the potassium currents of the cell with different effects according to the receptor subtype on which it acts.

Keyword

5-Hydroxytryptamine; Potassium channels; Vestibular nuclei

MeSH Terms

Animals
Digestion
Dihydroergotamine
Ether
Membranes
Neurons*
Patch-Clamp Techniques
Potassium Channels
Potassium*
Rats*
Rats, Sprague-Dawley
Serotonin 5-HT1 Receptor Agonists
Serotonin 5-HT2 Receptor Agonists
Serotonin*
Vestibular Nuclei
Dihydroergotamine
Ether
Potassium
Potassium Channels
Serotonin
Serotonin 5-HT1 Receptor Agonists
Serotonin 5-HT2 Receptor Agonists