Fig. 1. Dose–response curve of glutamate transporter, excitatory amino acid transporter type 3. Oocytes were injected with excitatory amino acid transporter type 3 mRNA and incubated at 16°C for 3 or 4 days before the current recording. (Top ) Typical current traces induced by the application of serial concentrations of l-glutamate are shown. Responses were quantified by integrating the current trace by quadrature. Data are mean ± SEM (n = 15–27). The minor ticks on the abscissa indicate double concentrations of the previous ticks on the log scale.