Table 1.
Effects of γ2 coexpression on heteromeric AMPA receptors in heterologous cells
|
|
|
Glu Pk (pA) |
Glu SS (pA) |
KA SS (pA) |
KA/Glu Pk(%) |
TPk/WCC (pA/pF) |
Desensitization (%) |
|---|---|---|---|---|---|---|---|
| AiBo (n = 15-17) | Con | 745 ± 168 | 6 ± 1 | 55 ± 12 | 11 ± 2 | 114 ± 27 | 99.4 ± 0.2 |
| γ2 | 4242 ± 646*** | 550 ± 107*** | 3625 ± 516*** | 92 ± 8*** | 350 ± 65** | 89.3 ± 1.7*** | |
| AiBi (n = 12-14) | Con | 1349 ± 442 | 64 ± 19 | 147 ± 48 | 12 ± 1 | 195 ± 48 | 97.7 ± 0.4 |
| γ2 | 3894 ± 592** | 989 ± 174*** | 2398 ± 426*** | 61 ± 6*** | 414 ± 66* | 84.0 ± 3.0*** | |
| AoBo (n = 10-14) | Con | 165 ± 48 | 3 ± 1 | 56 ± 15 | 35 ± 5 | 22 ± 5 | 99.3 ± 0.1 |
|
|
γ2 |
1843 ± 339***
|
205 ± 53**
|
3079 ± 537***
|
170 ± 11***
|
214 ± 42**
|
93.4 ± 1.1***
|
HEK293 cells were transfected with the AMPA receptor combinations shown with or without γ2 coexpression. Relative kainate (KA) efficacy is expressed as a percentage of the peak (Pk) response to 3 mm glutamate (Glu). Current density, as an assay for surface receptor expression, was determined by normalizing Glu plus TCM peak to whole-cell capacitance (TPk/WCC). Desensitization was calculated relative to maximal currents in the presence of TCM (% desensitization = [1 - (Glu SS/Glu + TCM peak)] × 100). The γ2 condition was significantly different from receptor alone (*p < 0.05; **p < 0.05; ***p < 0.001; t test). SS, Steady state; Con, control.