Channel properties of nAChR channels from C. elegans muscle cells in culture
Single-channel recordings were performed from muscle cells in culture obtained from wild-type and the specified mutant strains. ACh, ACh plus 10 μM DHβE, or levamisole was present in the pipette solution. The conductance, expressed in picosiemens, was taken from the slope of the current-voltage relationship (Fig. 1B) or from the current calculated at –100 mV. τ1 and τ2 correspond to the open components of the open time distributions. C1 and C2 are the closed components obtained from closed-time histograms. n corresponds to the number of recordings for each condition.
Agonist | Conductance | Concentration | τ1 | τ2 | C1 | C2 | ||
|---|---|---|---|---|---|---|---|---|
| pS | μM | μs | ms | |||||
| PD4251 (wild type) | ||||||||
| ACh | 38.7 ± 1.6 | 1 (n = 6) | 100 ± 20 | 280 ± 60 | 0.06 ± 0.01 | 180 ± 90 | ||
| 10 (n = 13) | 96 ± 23 | 320 ± 50 | 0.04 ± 0.02 | 40 ± 24 | ||||
| 50 (n = 8) | 140 ± 30 | 240 ± 20 | 0.05 ± 0.01 | 11 ± 6 | ||||
| 300 (n = 7) | 80 ± 10 | 0.04 ± 0.02 | 9 ± 4 | |||||
| ACh + 10 μM DHβE | 36.5 ± 1.7 | 50 (n = 5) | 170 ± 80 | 0.05 ± 0.02 | 12 ± 03 | |||
| Levamisole | 36.9 ± 0.8 | 0.1 (n = 6) | 140 ± 30 | 600 ± 70 | 0.05 ± 0.01 | 895 ± 240 | ||
| 1 (n = 5) | 270 ± 10 | 0.08 ± 0.01 | 220 ± 40 | |||||
| 10 (n = 8) | 150 ± 50 | 0.09 ± 0.01 | 24 ± 11 | |||||
| 100 (n = 4) | 120 ± 20 | 0.19 ± 0.07 | 5 ± 0.8 | |||||
| RB918 (acr-16) | ||||||||
| ACh | 36.8 ± 1.3 | 10 (n = 5) | 120 ± 40 | 280 ± 20 | 0.06 ± 0.01 | 68 ± 20 | ||
| Levamisole | 36.2 ± 2.6 | 0.1 (n = 6) | 90 ± 20 | 480 ± 60 | 0.04 ± 0.01 | 560 ± 120 | ||
| CB211 (lev-1) | ||||||||
| ACh | 26.0 ± 2.0 | 10 (n = 3) | 490 ± 20 | 0.05 ± 0.02 | 170 ± 40 | |||
| Levamisole | 28.3 ± 1.2 | 1 (n = 3) | 390 ± 30 |
| 0.07 ± 0.01 | 280 ± 20 | ||