The pharmacological characteristics of 5-HT3A-glvM3M4 are comparable to 5-HT3A. (A) Application of increasing 5-HT concentrations elicits inward currents with increasing amplitudes in 5-HT3A-glvM3M4–expressing oocyte. 5-HT concentrations (μM) are above corresponding trace. (B) Concentration–response relationship for 5-HT activation of 5-HT3A-glvM3M4 (closed squares) and 5-HT3A (open squares). Currents were normalized to the maximum response for individual oocytes (n = 8). (C) Coapplication of increasing picrotoxin concentrations with the 5-HT EC30 concentration to 5-HT3A-glvM3M4 inhibits 5-HT–activated currents. Picrotoxin concentrations (μM) are above corresponding trace. (D) Picrotoxin concentration–inhibition relationship for 5-HT3A-glvM3M4 (closed squares) and 5-HT3A (open squares) (n ≥ 3). (E) Diltiazem concentration–inhibition relationship. Experiments performed as in C except with diltiazem in place of picrotoxin (n ≥ 3). (F) GABA concentration–response curves for activation of GABA ρ1-glvM3M4 (closed squares) and GABA ρ1 (open squares) (n ≥ 3). In all panels, data points are mean ± SEM.
