Table 1.
Sensitivity to GABA and gelsemine of recombinant and native GABAARs.
| GABA sensitivity | Gelsemine sensitivity | |||||||
|---|---|---|---|---|---|---|---|---|
| GABAAR | EC50 (μM) | nH | Imax(pA) | N | IC50 (μM) | nH | Maximal modulation (%) | n |
| α1β2γ2 | 3.2 ± 0.2 | 1.8 ± 0.2 | 3,792 ± 257 | 6 | 66.8 ± 16.0 | 1.9 ± 0.7 | −44.3 ± 9.9 | 6 |
| α2β3γ2 | 29.8 ± 10.1 | 0.6 ± 0.1 | 1,958 ± 371 | 7 | 55.2 ± 13.7 | 1.2 ± 0.5 | −56.5 ± 4.9 | 6 |
| α3β3γ2 | 12.4 ± 5.5 | 0.5 ± 0.1 | 2,227 ± 475 | 6 | 55.6 ± 12.1 | 1.2 ± 0.5 | −63.5 ± 5.0 | 10 |
| α5β2γ2 | 5.4 ± 0.3 | 1.1 ± 0.1 | 1,428 ± 302 | 8 | 72.1 ± 7.9 | 0.7 ± 0.3 | −61.1 ± 3.8 | 6 |
| α1(H101R)β2γ2 | 2.3 ± 0.1 | 1.5 ± 0.2 | 1,946 ± 266 | 5 | – | – | – | – |
| α1β2 | 2.1 ± 0.1 | 1.6 ± 0.2 | 1,641 ± 271 | 6 | – | – | – | – |
| Native | 2.1 ± 0.5 | 1.0 ± 0.1 | 2,492 ± 568 | 12 | 89.1 ± 16.4 | 1.2 ± 0.1 | −49.6 ± 4.3 | 8 |
| + Gels. | 7.4 ± 1.0* | 1.2 ± 0.2 | 1,995 ± 434 | 12 | – | – | – | – |
Values of the concentration–response curve parameters (EC50 and Hill coefficients, nH) were obtained from the curve fits of normalized concentration–response data points from the indicated number of cells. The maximal current modulation was obtained using 300 μM of gelsemine. Results are presented as mean ± SEM. *p < 0.01, unpaired Student t-test, native versus gelsemine treated (+ Gels., 200 μM).