Figure 1. Temperature effects on voltage-gated Ca²⁺ currents IHCs.

A, I_Ca recorded from two IHCs at room and physiological temperature (P15). Currents were recorded by applying a 10 ms voltage step from the holding potential (i.e. −87 mV) to −27 mV. Capacitive transients were subtracted using a P/15 protocol. For room and physiological temperature, respectively: R_s= 5.5 mΩ and 5.8 mΩ; resting membrane capacitance = 9.7 pF and 9.7 pF; resting current at holding potential (−87 mV) =−1.7 pA and −12.2 pA. B, steady-state I–V at the different temperatures: steady-state amplitude was measured as the average over 4 ms starting 4 ms after the beginning of the 10 ms test pulse (n= 10). IV curves were fitted by a first order Boltzmann equation times the driving force (see text). C, calcium currents of A on expanded time scale. Activation kinetics time constant derived from the single exponential fit over 2 ms after the residual capacitive transients. D, tail current of A on expanded time scale. Tails current were best approximated by a double exponential fit (see text).