Competition
assays. (A) Sample currents and (B) concentration–response
relationships of GABA-current modulation by DA (105, 210, 400, and
750 μM) in oocytes expressing GABAρ1. DA concentration–response
curves of currents elicited by 1.7, 3.5, 7, and 21 μM GABA.
Notice that DA did not shift the GABA dose–responses curve
(P > 0.05). Data points are the means ± SEM
obtained from at least 9–11 oocytes from 5 frogs.