“At 10 μM, 30 μM and 100 μM, the ginkgolides caused rightward shifts of GABA dose –response curves and reduced maximal GABA responses, characteristic of noncompetitive antagonists, while the potencies showed a clear dependence on GABA concentration, indicating apparent competitive antagonism.”
“Kinetic modelling … the ginkgolides exhibit saturation of … high concentrations of GABA , but this was only partially observed for ginkgolide B. It also suggests that there may be different binding sites … the closed and open states of the receptor, with a higher affinity for the receptor in the closed state.”