Fig. 9.
Papain transforms voltage oscillations and outward currents in the semi-intact epithelium in situ. Traces from continuous perforated patch recordings taken before (control) and after perfusion of papain solution onto the epithelium. A, After 15 min in papain, the frequency of the voltage oscillations recorded in current-clamp increased from 36 Hz to 164 Hz. (Istim = 200 pA; Vrest = −72 mV in control and −91 mV after papain treatment). Traces are the average of 10 presentations.B, In another cell, the papain solution transformed the outward currents from those typical of hair cells in the semi-intact epithelial preparation (control) into currents typical of enzymatically dissociated hair cells (after 21 min in papain). The time constant for decay of the tail current after voltage steps to −36 mV decreased from 6.5 msec before enzyme treatment to 4.4 msec. The largest amplitude voltage step (corrected for series resistance errors) is indicated next to the step protocol.