Intracellular calcium suppresses mechano-electrical transduction current in chick cochlear hair cells.
Intracellular calcium concentration ([Ca2+]i) was elevated by photolysis of the caged calcium compound, Nitr-5, and by use of the intrapipette perfusion technique in hair cells dissociated from the chick cochlea. An increase in [Ca2+]i induced an outward-going current at a membrane potential of -40 mV, as recorded with an intracellular medium of 160 mM KCl. This current was carried by the Ca2+-activated K+ current. In contrast, an increase of [Ca2+]i induced an inward-going current at -50 mV with a 160 mM CsCl-based intracellular medium. This inward-going current was carried by the Ca2+-activated non-selective cation current. The amplitude of the mechano-electrical transduction current was suppressed by the increase of [Ca2+]i, achieved both by photolysis and by use of the intrapipette perfusion method.
Department of Otorhinolaryngology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
T
T
Kimitsuki
T
T
Taira
S
S
Komune
S
S
Komiyama
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002645:Chickens; D003051:Cochlea / Q000378:metabolism*; D046508:Culture Techniques; D004553:Electric Conductivity; D006198:Hair Cells, Auditory / Q000378:metabolism*; D010782:Photolysis
D002118:Calcium