Fig. 7.

Agonist-independent EAAT1 anion currents.A₁, Representative outside-out patch recording of steady-state d-aspartate (10 mm)-induced currents from an EAAT1-expressing oocyte. A₂, Record of the DHK blocked current (10 mm) from the same patch as in A₁. Records of both currents were measured in asymmetrical anion solutions (see below). B, Current–voltage plots of steady-state difference currents induced or blocked by application of d-aspartate (10 mm;filled symbols; n = 4) or DHK (10 mm; open symbols; n = 4). Outside-out patches expressing EAAT1 were recorded in asymmetrical anionic solutions [(110 mm Cl)_out and (100 mm SCN + 10 mm Cl)_in].C, Current–voltage plots (as in B), but with symmetrical anionic solutions [(100 mm SCN + 10 mm Cl)_out and (100 mm SCN + 10 mm Cl)_in]. Current amplitude has been normalized to d-aspartate-dependent currents measured at −100 mV. D, Correlation of the current induced by 10 mmd-aspartate and the current blocked by 10 mm DHK at −80 mV. Squares represent data obtained in asymmetrical anionic solutions (as in B) andcircles represent data obtained in symmetrical anion solutions (as in C). The slope of this line is 0.17.