Fig. 2.
Biophysical and pharmacological properties of the Aplysia HCN channel expressed in Xenopus laevis oocytes. (A and B) Inhibition of the acHCN channel by low concentrations of Cs+. (A) Ih current traces generated upon hyperpolarization from −30 mV to −110 mV in media with 2 mM Cs+ (red) or following washout (blue) were superimposed on the current trace generated under the same conditions in media without cesium (black). (B) I/V relationships for acHCN-mediated Ih in control conditions (black), in the presence of 2 mM Cs+ (red) or following washout (blue). The currents were normalized to the current value at −110 mV under the control conditions. Applying 2 mM Cs+ decreased Ih amplitude by 79.9 ± 2.7%, n = 4. (C and D) Applying 100 μM ZD7288 decreased the amplitude of Ih by 83.9 ± 2.4%; n = 4. (E and F) Applying 1 mM 8-Br-cAMP increased Ih amplitude by 18.0 ± 0.7%; n = 4. (G and H) Applying 1 mM 8-Br-cGMP increased Ih amplitude by 35.7 ± 20.3%; n = 4.