Figure 6. Role of the Na+ current in action potential activity.
a, A spontaneous action potential (AP: top trace) was used as a voltage command to elicit I Na (bottom trace) from the holding potential of −60 mV in four P2–P3 apical IHCs. The AP was recorded from an immature IHC under current clamp conditions at body temperature. b, Spontaneous action potential activity under current clamp recorded from a P2 basal IHC. The arrow indicates a spontaneous IPSP due to currents flowing through ACh receptors.