Journal article
Slow inactivation of sodium currents in the rat nodose neurons
Autonomic neuroscience, Vol.87(2), pp.209-216
2001
DOI: 10.1016/S1566-0702(00)00281-2
PMID: 11476281
Abstract
Nodose neurons express sodium currents that can be differentiated based on their sensitivity to tetrodotoxin. Several studies have demonstrated significant differences in voltage-dependence and kinetics of activation and inactivation between tetrodotoxin-sensitive and tetrodotoxin-resistant currents. However, little is known about the slow inactivation. Using whole cell patch-clamp technique fast and slow inactivation of sodium currents were studied in cultured rat nodose neurons. Tetrodotoxin-resistant currents recovered much more rapidly after a 15-ms depolarization than tetrodotoxin-sensitive currents. However, repeated 5-ms depolarizations at 10 Hz induced a cumulative inhibition that was more prolonged in tetrodotoxin-resistant compared to tetrodotoxin-sensitive currents. Consistent with these findings, slow inactivation proceeded more rapidly and was more complete for the tetrodotoxin-resistant than for tetrodotoxin-sensitive currents. While the voltage-dependence of fast inactivation differed significantly between the pharmacologically distinct currents, the voltage-dependence of slow inactivation was similar for both sodium currents. We conclude that slow inactivation of sodium currents can be triggered by trains of brief depolarizations. The resulting prolonged decrease in membrane excitability may contribute to the different patterns of action potential generation observed in primary afferent neurons.
Details
- Title: Subtitle
- Slow inactivation of sodium currents in the rat nodose neurons
- Creators
- Rubens Fazan - School of Medicine of Triangulo Mineiro, Department of Biological Science, Uberaba, MG, 38015-050, BrazilCarol A Whiteis - University of Iowa, Department of Internal Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USAMark W Chapleau - University of Iowa, Department of Internal Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USAFrancois M Abboud - University of Iowa, Department of Internal Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USAKlaus Bielefeldt - University of Iowa, Department of Internal Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA
- Resource Type
- Journal article
- Publication Details
- Autonomic neuroscience, Vol.87(2), pp.209-216
- Publisher
- Elsevier B.V
- DOI
- 10.1016/S1566-0702(00)00281-2
- PMID
- 11476281
- ISSN
- 1566-0702
- eISSN
- 1872-7484
- Language
- English
- Date published
- 2001
- Academic Unit
- Molecular Physiology and Biophysics; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984025479702771
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