Figure 1.

Increased Ca²⁺ efficiency of exocytosis in gerbil IHCs during maturation. A, B, I_Ca (middle) and ΔC_m (bottom) responses recorded from immature (black traces) and adult (gray traces) IHCs positioned in apical and basal regions of the cochlea, respectively. Recordings were obtained in response to 100 ms voltage steps from the holding potential of −81 to −20 mV or −11 mV, where the peak of the I–V curve occurred (Figs. 2B, 3B, bottom). The voltage protocol is shown above the traces. Unless otherwise stated, all recordings were at body temperature and used physiological 1.3 mm extracellular Ca²⁺.