Hyposmotic swelling induces magnitude and gain change in the electromotile performance of isolated outer hair cells.
OHCs were inserted into a partitioning microchamber. Reversible swelling was induced by hyposmotic incubation medium (270 mos.kg H2O-1). The transfer curve of electromotility was measured by stimulating the OHCs with a series of brief (2.5 ms) square-pulses with both polarities and graded magnitudes. Response magnitude and gain of electromotility were increased in swollen OHCs. On the basis of their electromotile performance-characteristics, swelling appeared to depolarize the OHCs. Transition from contraction dominated asymmetry of motility was observed towards a symmetric response. Depolarization, by itself, cannot explain the gain and magnitude increase. Acetylcholine (ACh) responsiveness of swollen OHCs preserves the pre-challenged pattern: ACh further increases gain and magnitude.
Sziklai
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I
ORL Clinic, Semmelweis Medical University, Budapest, Hungary. sziklai@sote.fulo.hu
Dallos
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P
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D048429:Cell Size; D004558:Electric Stimulation; D004594:Electrophysiology; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D009997:Osmotic Pressure
D000109:Acetylcholine