Transient expression of an inwardly rectifying potassium conductance in developing inner and outer hair cells along the mouse cochlea
| Autor: | Walter Marcotti, Corné J. Kros, Gwenaëlle S. G. Géléoc, G. W. T. Lennan |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Male
medicine.medical_specialty Patch-Clamp Techniques Potassium Channels Physiology Clinical Biochemistry Cesium In Vitro Techniques Membrane Potentials Mice Physiology (medical) Internal medicine Potassium Channel Blockers medicine Extracellular Animals RNA Messenger Patch clamp Potassium Channels Inwardly Rectifying Cochlea Membrane potential Hair Cells Auditory Inner Chemistry Potassium channel blocker Resting potential Electric Stimulation Potassium channel Electrophysiology Hair Cells Auditory Outer Endocrinology Barium Biophysics sense organs Algorithms medicine.drug |
| Zdroj: | Pflügers Archiv - European Journal of Physiology. 439:113-122 |
| ISSN: | 1432-2013 0031-6768 |
| DOI: | 10.1007/s004249900157 |
| Popis: | Inwardly rectifying K+ currents in inner and outer hair cells (IHCs, OHCs) were studied during post-natal development of the mouse cochlea. Hyperpolarizing steps from a holding potential of -64 mV induced a rapidly activating current in both cell types. This current showed strong inward rectification around the K+ equilibrium potential and, at potentials negative to -130 mV, partial inactivation. The activation range varied with extracellular K+ concentration. External application of Ba2+ and Cs+ reversibly blocked the elicited current. The results are consistent with the presence of an IK1-type inwardly rectifying potassium conductance in these cells. The maximum current was 60% larger in IHCs than in OHCs. In OHCs, but not IHCs, the amplitude of IK1 varied significantly with the cells' position along the cochlea. IK1 was maximal in cells located in the most basal region of the cochlea and its amplitude decreased in the apical coil. IK1 disappeared upon functional maturation: in OHCs at the end of the first postnatal week, and in IHCs at the onset of auditory function 12 days after birth. The current is active at the resting potential of the cells and plays a role in regulating the spiking behaviour characteristic of developing hair cells. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink