Biophysical properties of NR1R, NR1Q and WT receptor currents Results from 3-s applications of 1 mM glutamate/50 μM glycine with 1-2 μM TPEN. n = 6 to 15 different cells for all kinetic parameters; n = 4-7 different cells for EC50 measurements.
| NR1Ra | WTb | NR1Q 0 Ca2+ | NR1Q 1.8 mM Ca2+ | |
|---|---|---|---|---|
| 10—90% | 13.4 ± 0.3 | 6.4 ± 0.2 | 6.7 ± 0.4 | 6.8 ± 0.3 |
| Rise time (ms) | ||||
| τD (ms) | ||||
| τDf | 54 ± 6.5 (32%) | 29 ± 3 (67%) | ||
| τDs | 4040 ± 680 (100%) | 1610 ± 110 (100%) | 1400 ± 110 (68%) | 5770 ± 1580 (33%) |
| τresens (s) | 20.2 ± 0.70 | 2.42 ± 0.27 | 14.3 ± 0.54 | N.D. |
| Iss/Ipeak | 0.93 ± 0.01 | 0.74 ± 0.03 | 0.54 ± 0.04 | 0.63 ± 0.03 |
| τoff (ms) | ||||
| τoff,f | 170 ± 17 (61%) | 56 ± 9 (89%) | 89 ± 11 (100%) | 122 ± 13 (62%) |
| τoff,s | 611 ± 42 (39%) | 309 ± 49 (11%) | 539 ± 45 (38%) | |
| EC50 (μM; peak current): | 1.9 ± 0.2 | 7.7 ± 0.8 | N.D. | 8.1 ± 0.5 |
N.D. not determined.
↵ a Time course of glutamate-evoked response was not different for individual NR1R-expressing cells switched between external solutions containing no added extracellular Ca2+ versus 1.8 mM CaCl2, therefore these data were pooled
↵ b Results from experiments with no added extracellular Ca2+ for WT