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The delayed rectifier, IKI, is the major conductance in type I vestibular hair cells across vestibular end organsHair 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.
Document ID
20040173229
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ricci, A. J. (University of Texas Medical Branch at Galveston Galveston TX 77555-1063, United States)
Rennie, K. J.
Correia, M. J.
Date Acquired
August 22, 2013
Publication Date
May 1, 1996
Publication Information
Publication: Pflugers Archiv : European journal of physiology
Volume: 432
Issue: 1
ISSN: 0031-6768
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: DCO1273
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Number 40-99
NASA Discipline Neuroscience
Non-NASA Center
NASA Program Space Biology Research Associates