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Electrical filtering in gerbil isolated type I semicircular canal hair cells1. Membrane potential responses of dissociated gerbil type I semicircular canal hair cells to current injections in whole cell current-clamp have been measured. The input resistance of type I cells was 21.4 +/- 14.3 (SD) M omega, (n = 25). Around the zero-current potential (Vz = -66.6 +/- 9.3 mV, n = 25), pulsed current injections (from approximately -200 to 750 pA) produced only small-amplitude, pulse-like changes in membrane potential. 2. Injecting constant current to hyperpolarize the membrane to around -100 mV resulted in a approximately 10-fold increase in membrane resistance. Current pulses superimposed on this constant hyperpolarization produced larger and more complex membrane potential changes. Depolarizing currents > or = 200 pA caused a rapid transient peak voltage before a plateau. 3. Membrane voltage was able to faithfully follow sine-wave current injections around Vz over the range 1-1,000 Hz with < 25% attenuation at 1 kHz. A previously described K conductance, IKI, which is active at Vz, produces the low input resistance and frequency response. This was confirmed by pharmacologically blocking IKI. This conductance, present in type I cells but not type II hair cells, would appear to confer on type I cells a lower gain, but a much broader bandwidth at Vz, than seen in type II cells.
Document ID
20040173225
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Rennie, K. J.
(University of Texas Medical Branch Galveston 77555-1063, United States)
Ricci, A. J.
Correia, M. J.
Date Acquired
August 22, 2013
Publication Date
May 1, 1996
Publication Information
Publication: Journal of neurophysiology
Volume: 75
Issue: 5
ISSN: 0022-3077
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: 5 F32 DC-00169-01
CONTRACT_GRANT: DC-01273
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Neuroscience

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