Figure 4.
zGlyRα subunits form functional homomeric receptors that are activated by glycine, and inhibited by strychnine and picrotoxin. (A) Two-electrode voltage-clamp recording from an oocyte injected with five femtomoles of zGlyRα1 cRNA exposed to serial application of glycine of increasing amount. Ten oocytes were used for each assay. (B) Cumulative dose-response relationship of glycine-evoked currents. The amplitude of each glycine-evoked response was normalized to the maximally-evoked current for each oocyte (n = 10). Values here and elsewhere represent the average ± SEM. Dashed line denotes EC50. (C,E) Recordings from oocytes exposed to glycine and increasing amounts of strychnine or picrotoxin, respectively (n = 10). (D,F) Cumulative dose-response relationships of strychnine and picrotoxin-blocked currents (n = 10). Extent of blockade was normalized to the current amplitude evoked by 200 μM glycine in each oocyte. Dashed lines denote IC50s.