Recovery from inactivation was measured by administering
an extended prepulse to fully inactivate the current, then repolarizing
the cell and measuring the current elicited by a test
pulse after a certain delay. In this manner, recovery could be
distinguished from phenomena such as facilitation or inactivation
from intermediate closed states. The initial experiments
investigated the time course of recovery after repolarization to
3110 mV. As other studies have shown [15,16], recovery of
the calcium current is best ¢t by a biexponential function. The
parameters of curves ¢t to individual experiments varied