Figure 7. Effects of carbachol on I_HA and I_DA.

A, the control I-V relationship was measured as described for Fig. 6C. After I_HA had developed in divalent cation-free, high-Cs⁺ external solution, it was rapidly potentiated by carbachol (CCh) application. I_DA was abolished in Cs⁺-containing external solution and was inactivated at −40 mV. B, in a different cell, I_DA measured at −40 mV in divalent cation-free, high-Na⁺ external solution was strongly inhibited by carbachol.