細胞内カルシウムイオン増加による蝸牛有毛細胞トランスデューサー電流への影響

抄録

Intracellular Ca²⁺ concentration was raised by photolysis of the caged calcium compound, Nitr-5, and by the intra-pipette perfusion technique. Increase of intracellular Ca²⁺ induced an outward current at the membrane potential of -40mV when recorded with an intracellular medium of 160mM KCl. This outward current was carried through the Ca²⁺-activated K channel. While increase of intracellular Ca²⁺ induced an inward current at -50mV with an 160mM CsCl-based intracellular medium. This inward current was carried through the Ca²⁺-activated non-selective cation channel. The amplitude of the mechano-electrical transduction current was reduced by the increase of intracellular Ca²⁺ both by the photolysis and by the intra-pipette perfusion methods.