Inhibitory Effects of Norepinephrine on the Potassium Current of Rat Medial Vestibular Nuclear Neurons.
- Author:
Han Seong JEONG
1
;
Myung Joo JANG
;
Mei HUANG
;
Hae Ryong HUH
;
Ki Hyun CHO
;
Byeong Chae KIM
;
Jong Seong PARK
Author Information
1. Department of Physiology, Chonnam National University Medical School, Gwangju, Korea. parkjs@chonnam.ac.kr
- Publication Type:Original Article
- Keywords:
Norepinephrine;
Vestibular Nucleus;
Potassium current
- MeSH:
4-Aminopyridine;
Animals;
Delayed Rectifier Potassium Channels;
Digestion;
Ether;
Neurons*;
Norepinephrine*;
Patch-Clamp Techniques;
Potassium*;
Rats*;
Rats, Sprague-Dawley;
Tetraethylammonium;
Vestibular Nuclei
- From:Journal of the Korean Neurological Association
2005;23(3):363-367
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: This study aimed to explore the effects of norepinephrine on the potassium currents of rat medial vestibular nuclear neurons by using the whole-cell patch clamp technique. METHODS: Sprague-Dawley rats aged 14 to 16 days were anesthetized with ether and decapitated. After enzymatic digestion, the portion of the medial vestibular nucleus neurons were obtained by micropunching. The dissociated neurons were transferred into a recording chamber mounted on an inverted microscope and potassium currents were recorded by standard patch-clamp techniques under voltage-clamp modes. RESULTS: Norepinephrine inhibited the whole potassium currents of the medial vestibular nuclear neurons. Outward potassium currents were more suppressed in 4 mM 4-aminopyridine and norepinephrine added solutions than 4 mM 4-aminopyridine only, but were not suppressed in 10 mM tetraethylammonium and norepinephrine added solutions compared to 10 mM tetraethylammonium only. CONCLUSIONS: These results suggest that norepinephrine blocks the delayed rectifier potassium channels in medial vestibular nuclear neurons.
