Figure 8.
Paired recordings and simultaneous ΔCm measurements. A–C, EPSCs mediated by AMPA receptors are not significantly desensitized or saturated during exocytosis with pairs of 20 ms (A, B) or 200 ms (C) depolarizing pulses from a holding potential of −90 to −30 mV in hair cell synapses. Presynaptic ICa, Cm (gray open circle, bottom), and afferent fiber EPSC were simultaneously recorded while a voltage-clamped hair cell was depolarized by a pair of 20 ms pulses with 20 ms interpulse interval (A), by a pair of 20 ms pulses with 200 ms interpulse interval (B), or by a pair of 200 ms pulses with 50 ms interpulse interval (C). The intermediate changes of EPSC charge transfer (black lines) are well correlated with the increases of ΔCm (gray open circles) after the traces are normalized to the peak EPSC and ΔCm changes.