(A) In this particular patch, seven consecutive ramps to the temperature indicated were applied with an interval of 30 s to produce ~60% inactivation. The patch was left at the bath temperature (21.8°C) for a 2 min recovery period, after which another identical activation ramp did not elicit a current larger than the residual current after inactivation, indicating absence of recovery from inactivation. (B) Another patch was subjected to five activation ramps that produced ~80% inactivation. This time, during the 2 min recovery period, bath temperature was lowered to between 12 and 13°C. Again, no current was produced by an activation ramp, indicating no recovery. Maximal temperature during the ramp is indicated in each panel. (C) Summary of results from several experiments indicating no recovery of current after a 2 min period at normal bath temperature (~22°C, blue circles) or in a cooled bath (10°C, purple circles). Statistical difference was tested with a Student-t test, n.s. indicates no difference (p>0.2). (D) Similar to (A) but in this patch the current was elicited by a ramp to a larger temperature, indicated in each panel, which produced a larger inactivation in a single ramp (80%). After a 2 min period at 21°C, no current was recovered. (E) Same as in (C) but with a recovery period at 10°C. No recovery of current is evident. (F) Summary of results from several experiments as in (D) and (E) indicating no recovery of current after a 2 min period at normal bath temperature (~22°C, blue circles) or in a cooled bath (10°C, purple circles). Absence of significant recovery was based on a Student t-test with p>0.2. The label n.s. indicates non-significance. (G) No recovery of current is observed with a longer recovery period of 20 min at 0 mV or at −60 mV (H). (I) Summary of recovery of five patches held at 0 mV for 20 min after current inactivation (blue circles) and three patches held at −60 mV for 20 min after current inactivation (orange squares). No current is recovered, regardless of the fraction of inactivated current.