FIGURE 4.

Pharmacological characterization of AmGABA receptors. (a) Effect of 50‐μM bicuculline on 100‐μM GABA‐evoked current from oocyte expressing AmRDL, AmRDL/LCCH3, AmRDL/GRD, or AmLCCH3/GRD (n = 5). All RDL‐containing receptors are insensitive, and AmGRD/LCCH3 is slightly sensitive to bicuculline at 50 μM. (b–e) Concentration‐dependent inhibitory curves obtained from oocytes expressing AmRDL, AmRDL/LCCH3, AmRDL/GRD, or AmLCCH3/GRD; 100‐μM GABA‐evoked current are blocked by successive applications of increasing concentrations of fipronil (n = 11) (b), picrotoxin (n = 12) (c), dieldrin (n = 7) (d), and ivermectin (n = 9) (e). (f) Representative examples of two successive 100‐μM GABA‐evoked currents, spaced by 5 min in the presence of 500‐nM ivermectin, recorded in oocytes expressing AmRDL or AmLCCH3/GRD. The black traces represent the initial GABA‐evoked current, and the red traces show the second one (up). Mean values (n = 7) of the pre‐incubation block with ivermectin on AmRDL, AmRDL/LCCH3, AmRDL/GRD, or AmLCCH3/GRD (bottom). *P < .05, significantly different as indicated; Holm–Sidak method