Gadolinium blocks mechano-electric transducer current in chick cochlear hair cells

We investigated the effects of gadolinium ion (Gd 3+) on the mechano-electrical transduction (MET) current using a whole-cell patch electrode voltage clamp technique in dissociated cochlear hair cells of chicks. Gd 3+ blocked the MET channel in a concentration- and voltage-dependent manner. At −50 mV, Gd 3+ blocked the MET channel, with a Hill coefficient of 1.14 and a dissociation constant ( K D) of 1.01 × 10 −5 M. Adaptation of the MET current disappeared after the introduction of Gd 3+, a change that may be due to a decrease in inward going MET currents, specifically the Ca 2+ component.