ID 111078
Author
Banzrai, Chimeglkham Tokushima University
Okada, Ryo Tokushima University
Higashi, Saki Tokushima University
Osaki, Yusuke Tokushima University
Keywords
axonal excitability
ion channels
membrane potential
slow K+ channel
HCN channel
Content Type
Journal Article
Description
Maintenance of axonal excitability relies on complex balance by multiple ion currents, but its evaluation is limited by in vitro single channel neurophysiological study on overall behavior. We sought to evaluate behaviors of multiple ion currents by pharmacological blockade. The threshold tracking technique was used to measure multiple excitability indices on tail sensory nerve of normal male mice before and after administration of either BaCl2 or ivabradine. Mathematical modeling was used to identify the interval changes of the channel parameters. After administration of BaCl2 and ivabradine, the following changes were present : greater threshold changes of both depolarizing and hyperpolarizing threshold electrotonus by both ; additionally, reduced S2 accommodation, reduced late subexcitability and increased superexcitability by BaCl2, increased S3 accommodation by ivabradine. Mathematical modelling implied reduction of slow K+ conductance, along with reduction of H conductance (Ih) by BaCl2 ; and reduction of Ih while augmentation of K+ conductances by ivabradine. Pharmacological blockade of a selective ion channelmay be compensated by other ion channels. Unintended effects by ion channel modification could be caused by secondary current alteration by multiple ion channels.
Journal Title
The Journal of Medical Investigation
ISSN
13496867
13431420
NCID
AA11166929
AA12022913
Publisher
Faculty of Medicine Tokushima University
Volume
64
Issue
1-2
Start Page
30
End Page
38
Sort Key
30
Published Date
2017-02
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Medical Sciences