The acquisition during development of Ca-activated potassium currents by cochlear hair cells of the chick.
Voltage-clamp recordings were done on hair cells from a region of the chick's cochlea. In the adult, these cells have voltage-sensitive Ca currents and rapid, Ca-activated K currents that together support an electrical resonance, showing voltage oscillations at frequencies greater than 100 Hz. In embryos 14-days old (at one week before hatching) the same cells had a voltage-sensitive Ca current like that in adults, but a more slowly acting K current (of the delayed-rectifier type). In current-clamp they could generate only slowly repetitive action potentials. By two days before hatching, Ca-activated K currents were present. We suggest that the acquisition of Ca-activated K currents contributes to functional maturation of the chick's cochlea.
Fuchs
P A
PA
Department of Physiology, University of Colorado Health Sciences Center, Denver 80262.
Sokolowski
B H
BH
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002462:Cell Membrane / Q000502:physiology; D002586:Cesium / Q000494:pharmacology; D002642:Chick Embryo; D002645:Chickens; D002712:Chlorides; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000196:embryology / Q000502:physiology*; D066298:In Vitro Techniques; D008564:Membrane Potentials; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D002712:Chlorides; D015221:Potassium Channels; D002586:Cesium; C028019:cesium chloride; D002118:Calcium