Figure 4. Measurement of the apparent affinity of 2AR for serotonin using ion channel activity.
(A) Representative barium-sensitive traces of KIR2.3 currents obtained in oocytes expressing 2AR in response to increasing concentrations (0.1 nM to 1 mM) of serotonin (SER). (B) Dose-response curve showing Gq-mediated inhibition of KIR2.3 current elicited by serotonin in oocytes expressing 2AR. Response was normalized to the maximum value. (EC50 = 214 ± 0.01 nM).