Abstract
Voltage-dependent channels in outer hair cells (OHCs) dissociated from the guinea pig cochlea were investigated by the use of a whole-cell patch-clamp technique. Two types of K+ current were recorded from OHCs. One was a slowly inactivating K+ current that was activated at a potential more positive than −30 mV. Another is a K+ current that was already activated at resting membrane potential. After suppressing both K+ currents, depolarizing voltage steps elicited a slowly inactivating inward current that was dependent on external Ca2+ and was indicative of an L-type Ca2+ channel in OHCs. Aminoglycoside antibiotics known to be ototoxic selectively inhibited the Ca2+ current.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ashmore JF (1987) A fast motile response in guinea-pig outer hair cells: the cellular basis of the cochlea amplifier. J Physiol (Lond) 388:323–347
Ashmore JF, Meech RW (1986) Ionic basic of membrane potential in outer hair cells of guinea pig cochlea. Nature 322: 368–371
Bobbin RP, Jadtreboff PJ, Fallon M, Littman T (1990) Nimodipine, an L-channel Ca2+ antagonist, reverses the negative summating potential recorded from the guinea pig cochlea. Hear Res 46:277–288
Brownell WE, Bader CR, Betrand D, Ribaupierre Y (1985) Evoked mechanical responses of isolated cochlear outer hair cells. Science 227:194–196
Corey DP, Hudspeth AJ (1983) Analysis of the microphonic potential of the bullfrog's sacculus. J Neurosci 3:942–961
Dallos P, Corey ME (1991) The role fo outer hair cell motility in cochlear tuning. Curr Opin Neurobiol 1:215–220
Dallos P, Santos-Sacchi J, Flock Å (1982) Intracellular recordings from cochlear outer hair cells. Science 218:582–584
Fuchs PA, Evans MG (1990) Potassium currents in hair cells isolated from the cochlea of the chick. J Physiol (Lond) 429: 529–551
Housley GC, Ashmore JF (1992) Ionic currents of outer hair cells isolated from the guinea pig cochlea. J Physiol (Lond) 448: 73–98
Kakehata S, Nakagawa T, Takasaka T, Akaike N (1993) Cellular mechanism of acetylcholine-induced response in dissociated outer hair cells of guinea-pig cochlea. J Physiol (Lond) 359:189–217
LePage EL (1989) Functional role of the olivo-cochlear bundle: a motor unit control system in the mammalian cochlea. Hear Res 38:177–198
Nakagawa T, Akaike N, Kimitsuki T, Komune S, Arima T (1990) ATP-induced current in isolated outer hair cells of guinea pig cochlea. J Neurophysiol 63:1068–1074
Nakagawa T, Kakehata S, Akaike N, Komune S, Takasaka T, Uemura T (1991) Calcium channel in isolated outer hair cells of guinea pig cochlea. Neurosci Lett 125:81–84
Nakagawa T, Kakehata S., Akaike N, Komune S, Takasaka T, Uemura T (1992) Effects of Ca2+ antagonists and aminoglycoside antibiotics on Ca2+ current in isolated outer hair cells of guinea pig cochlea. Brain Res 580:345–347
Newman EA, Främbach DA, Odette LL (1984) Control of extracellular potassium levels by glial cell K+ siphoning. Science 225:1174–1175
Ohmori H (1985) Mechano-electrical transduction currents in isolated vestibular hair cells of the chick. J Physiol (Lond) 359: 189–217
Schacht J (1986) Molecular mechanisms of drug-induced hearing loss. Hear Res 22:297–304
Sugihara I, Furukawa T (1989) Morphological and functional aspects of two different type of hair cells in the goldfish sacculus. J Neurophysiol 62:1330–1343
Witt CM, Brownell WE, Betrand D (1993) Unexpected sodium current in guinea pig outer hair cells. Abstr 16th Midwinter Meeting ARO:318
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nakagawa, T., Kakehata, S., Akaike, N. et al. Voltage-dependent channels in dissociated outer hair cells of the guinea pig. Eur Arch Otorhinolaryngol 251 (Suppl 1), S57–S60 (1994). https://doi.org/10.1007/BF02565221
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02565221