Figure 5.

ED promotes reverse glutamate transport. (A) Glutamate heteroexchange increases during ED. Sample trace showing that brief (300 ms) tPDC applications induce progressively more release of glutamate during ED. (A2) Pooled data; n = 7. (B) Glutamate efflux can occur during reverse transport or during heteroexchange. Pulses of tPDC will shift the transporter into the “glu/3Na⁺/H⁺ inside” state. The glutamate binding site is then returned to the outside through transport of either K⁺ or glutamate. During ED, the latter pathway (common to heteroexchange and reverse transport) is favored. See Results for details. This figure is adapted from refs. 22 and 24.