Document Detail


The delayed rectifier, IKI, is the major conductance in type I vestibular hair cells across vestibular end organs.
MedLine Citation:
PMID:  8662265     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Hair cells were dissociated from the semicircular canal, utricle, lagena and saccule of white king pigeons. Type I hair cells were identified morphologically based on the ratios of neck width to cuticular plate width (NPR < 0.72) as well as neck width to cell body width (NBR < 0.64). The perforated patch variant of the whole-cell recording technique was used to measure electrical properties from type I hair cells. In voltage-clamp, the membrane properties of all identified type I cells were dominated by a predominantly outward potassium current, previously characterized in semicircular canal as IKI. Zero-current potential, activation, deactivation, slope conductance, pharmacologic and steady-state properties of the complex currents were not statistically different between type I hair cells of different vestibular end organs. The voltage dependence causes a significant proportion of this conductance to be active about the cell's zero-current potential. The first report of the whole-cell activation kinetics of the conductance is presented, showing a voltage dependence that could be best fit by an equation for a single exponential. Results presented here are the first data from pigeon dissociated type I hair cells from utricle, saccule and lagena suggesting that the basolateral conductances of a morphologically identified population of type I hair cells are conserved between functionally different vestibular end organs; the major conductance being a delayed rectifier characterized previously in semicircular canal hair cells as IKI.
Authors:
A J Ricci; K J Rennie; M J Correia
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Pflügers Archiv : European journal of physiology     Volume:  432     ISSN:  0031-6768     ISO Abbreviation:  Pflugers Arch.     Publication Date:  1996 May 
Date Detail:
Created Date:  1997-04-08     Completed Date:  1997-04-08     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0154720     Medline TA:  Pflugers Arch     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  34-42     Citation Subset:  IM; S    
Affiliation:
Department of Otolaryngology , MRB, Rt. J-63, University of Texas Medical Branch at Galveston, Galveston TX 77555-1063, USA.
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MeSH Terms
Descriptor/Qualifier:
4-Aminopyridine / pharmacology
Animals
Columbidae
Electric Conductivity
Electrophysiology
Hair Cells, Vestibular / drug effects,  physiology*,  ultrastructure
Homeostasis
Kinetics
Models, Neurological
Potassium / physiology*
Grant Support
ID/Acronym/Agency:
DCO1273/DC/NIDCD NIH HHS
Chemical
Reg. No./Substance:
504-24-5/4-Aminopyridine; 7440-09-7/Potassium
Investigator
Investigator/Affiliation:
A J Ricci / U WI, Madison

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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