Table 1.
GlyR sensitivities to glycine and Zn2+
| GlyR subtype | Gly EC50 (μm) | Imax (nA) | n | Zn2+ IC50 (μm) | n |
|---|---|---|---|---|---|
| α1 | 24 ± 5 | 4.5 ± 0.5 | 10 | 15 ± 2 | 5 |
| α2 | 66 ± 6 | 3.7 ± 0.5 | 13 | 360 ± 40 | 11 |
| α1 β | 18 ±3 | 4.5 ± 0.9 | 6 | 13 ± 2 | 3 |
| α2 β | 51 ± 4 | 5.6 ± 0.5 | 3 | 180 ± 30 | 13 |
| α1H107N | 24 ± 2 | 5.9 ± 0.3 | 4 | 230 ± 30 | 5 |
| α1H109F | 56 ± 5 | 5.1 ± 0.2 | 3 | > 1 mm | 3 |
| α1T133A | 130 ± 30 | 4.8 ± 0.7 | 5 | > 1 mm | 5 |
| α1T135A | 17 ± 2 | 3.3 ± 0.6 | 3 | 26 ± 6 | 3 |
| α1H107NβN130H | 28 ± 8 | 4.8 ± 0.8 | 3 | 24 ± 3 | 5 |
| α1H109FβS156T | 39 ± 4 | 5.2 ± 1.2 | 3 | > 1 mm | 3 |
| α1T133AβS156T | 90 ± 16 | 3.2 ± 0.9 | 3 | > 1 mm | 3 |
| α1 βS156A | 44 ± 9 | 5.9 ± 0.7 | 3 | 17 ± 7 | 3 |
| α2N114H | 58 ± 3 | 4.2 ± 0.7 | 3 | 29 ± 2 | 4 |
| α2 βG128S | 52 ± 5 | 5.0 ± 1.6 | 3 | 170 ± 20 | 4 |
| α2 βS156T | 47 ± 9 | 5.6 ± 1.4 | 3 | 210 ± 20 | 5 |
| α3 | 48 ± 3 | 5.3 ± 1.3 | 4 | 150 ± 10 | 4 |
| α3N107H | 53 ± 12 | 5.3 ± 0.8 | 5 | 26 ± 7 | 3 |
| sc 5 DIV | ∼ 40 | 3.1 ± 0.3 | 12 | 320 ± 50 | 8 |
| sc 7 DIV | ∼ 30 | 4.9 ± 0.7 | 12 | 110 ± 10 | 8 |
| sc 10–14 DIV | ∼ 30 | 4.3 ± 0.4 | 8 | 88 ± 21 | 8 |
The values indicate the glycine EC50 values for activating the recombinant and native GlyRs and also the Zn2+ IC50 values for modulating the half-maximal glycine-activated responses where Zn2+ is first pre-equilibrated with the receptor for 15 s before an equivalent concentration of Zn2+ is coapplied with glycine. All numbers are means ± s.e.m. from n cells. For the native GlyR in spinal cord (sc) neurones, the EC50 values were estimated from linear segments of the dose–response curves.