Effects of Phenylephrine on the Excitability of Medial Vestibular Nuclear Neurons in Rats.
- Author:
Han Seong JEONG
1
;
Hae Ryong HUH
;
Myung Joo JANG
;
Seol Hee HONG
;
Sujeong JANG
;
Jin PARK
;
Seung Han LEE
;
Jae Ha 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:
Medial vestibular nucleus;
Phenylephrine;
Action potential;
Potassium currents
- MeSH:
Action Potentials;
Animals;
Digestion;
Locus Coeruleus;
Membrane Potentials;
Neurons*;
Patch-Clamp Techniques;
Phenylephrine*;
Potassium;
Rats*;
Rats, Sprague-Dawley;
Vestibular Nuclei
- From:The Korean Journal of Physiology and Pharmacology
2006;10(3):131-135
- CountryRepublic of Korea
- Language:English
-
Abstract:
Coeruleo-vestibular pathway which connects locus coeruleus and vestibular nuclei is noradrenergic. This study was designed to elucidate the effects of phenylephrine on the spontaneous activity of acutely isolated medial vestibular nuclear neurons of rat by whole-cell patch-clamp technique. Sprague-Dawley rats, aged 14 to 16 days, were used. After enzymatic digestion, dissociated medial vestibular neurons were transferred to a recording chamber mounted on an inverted microscope, and spontaneous action potentials were recorded by standard patch-clamp techniques. In current-clamp mode, the frequency of spontaneous action potential of medial vestibular nuclear neurons was decreased by phenylephrine (n=15). Phenylephrine increased the amplitude of afterhyperpolarization without changes in the resting membrane potential and spike width. In voltage-clamp mode, the whole potassium currents of the medial vestibular nuclear neurons were increased by phenylephrine (n=12). These experimental results suggest that alpha-receptor mediates the inhibitory effects on the neuronal activity of the medial vestibular nuclear neuron.
