Kinetic parameters of glutamate transporter anion currents with different intracellular solutions
| Pipette contents (in mm): | 140 KSCN, 0 glutamate | 130 KSCN, 10 K-glutamate | 135 KSCN, 5 NaSCN, 5 Na-glutamate | 130 NaSCN, 10 Na-glutamate |
|---|---|---|---|---|
| Brief pulse, τ (msec) | 8.6 ± 0.5 (21) | 12.8 ± 3 (3) | 22 ± 5.3 (4)* | 54 ± 12 (2)* |
| 9.6 | 9.6 | 19.6 | 47.8 | |
| Long pulse, τ (msec) | 9.4 ± 0.5 (28) | 13.2 ± 1.4 (5)* | 11 ± 0.6 (4) | 12 ± 1.9 (6) |
| 11.9 | 12.1 | 9.2 | 5.1 | |
| Iss/ IPEAK(%) | 13.5 ± 2 (29) | 11 ± 3 (5) | 31 ± 5 (4)* | 78 ± 4 (10)* |
| 11.3 | 9.5 | 35 | 71.5 |
The decay of responses to brief pulses was best described by two exponential components in the 135 KSCN, 5 Na-SCN, 5 Na-glutamate and in the 130 Na-SCN, 10 Na-glutamate conditions. The time constants reported are of the form τ = A1 × τ1 + A2 × τ2, where A1 and A2 are the fractions of the decay contributed by each time constant.Bold values are from identical analysis of simulations generated by the model in Figure 6. An asterisk denotes a significant difference at a level of p < 0.05 from the 140 KSCN, 0 glutamate condition.