Abstract
We have investigated the maturation of adult hair cell electrophysiology in a population of precursor cells in a conditionally immortal cell line. The cell line, UB/OC-2, from the embryonic organ of Corti of the H-2Kb-tsA58 transgenic mouse, permits cells to grow proliferatively at 33°C and to differentiate at 39°C. Whole-cell patch-clamp recordings showed that proliferating cells had a different electrophysiology to differentiating cells. Differentiating cells had a conditionally expressed slowly activating inward current activated by hyperpolarization. The current was not blocked by extracellular application of 0.5 mM Ba2+, but was blocked reversibly by 2 mM Cs+. The current was found to be carried by both K+ and Na+ ions (P K/P Na=2.2) and activated by 10 µM forskolin. These properties identify the slowly activating current as I h. A proportion of proliferating and differentiating cells exhibited a voltage-gated Na+ current, I Na. I Na was abolished in Na-free external medium and was inhibited reversibly by tetrodotoxin (TTX) with K i=64 nM. Together these results suggest that proliferating and differentiating hair cell precursors in the immortal cochlear cell line UB/OC-2 express currents which are also found in developing hair cells.
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Received: 6 January 1999 / Received after revision: 1 February 1999 / Accepted: 2 February 1999
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Jagger, D., Holley, M. & Ashmore, J. Ionic currents expressed in a cell line derived from the organ of Corti of the Immortomouse. Pflügers Arch 438, 8–14 (1999). https://doi.org/10.1007/s004240050873
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DOI: https://doi.org/10.1007/s004240050873