Fig. 4. Representative traces from three cells illustrating the effects of local anesthetics on the slow-inactivating transient current. Effects of bupivacaine (BUP, A ), lidocaine (LID, B ), and tetracaine (TET, C ). All three local anesthetics decrease the slow-inactivating transient current in a concentration-dependent manner. In the presence of bupivacaine, the decay was well-described by a biexponential equation as described in the Methods.