Table 1.
Temperature dependence of transducer I(X) relations and adaptation
| Temperature |
I(X) parameters |
Adaptation at X1/2 |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Stimulus (n) | Imax, pA | OR, nm | Po | X1/2, nm | τfast, ms | τslow, ms | Percent decay | Percent Aslow | |
| 27°C | Step | ||||||||
| Peak (6) | 148 ± 14 | 1221 ± 161 | 0.12 ± 0.02 | 374 ± 45 | 4.7 ± 0.7 | 56 ± 9 | 79 ± 5 | 45 ± 4 | |
| Steady-state (6) | 58 ± 10 | 1403 ± 247 | 0.12 ± 0.04 | 634 ± 172 | |||||
| 0.6–1 μm Sine | |||||||||
| 100 Hz (13) | 144 ± 12 | 1056 ± 97 | 0.16 ± 0.03 | 405 ± 43 | |||||
| 2 Hz (12) | 96 ± 6 | 1263 ± 66 | 0.51 ± 0.05 | −20 ± 55 | |||||
| 37°C | Step | ||||||||
| Peak (7) | 233 ± 30, p < 0.03a | 902 ± 58 | 0.13 ± 0.02 | 311 ± 23 | 3.6 ± 0.2b | 58 ± 6 | 77 ± 3 | 36 ± 4 | |
| Steady-state (7) | 94 ± 15, p < 0.001c | 1244 ± 152 | 0.13 ± 0.03 | 437 ± 26 | |||||
| 0.6–1 μm Sine | |||||||||
| 100 Hz (12) | 241 ± 25, p < 0.001d | 1178 ± 59 | 0.22 ± 0.03 | 348 ± 42 | |||||
| 2 Hz (10) | 155 ± 18, p < 0.003e | 1394 ± 129 | 0.34 ± 0.05, p < 0.03 | 213 ± 69, p < 0.02 | |||||
Maximum current (Imax) valuesa,c,d,e were larger at 35–39°C (represented by the midpoint “37°C”) than at 25–29°C (“27°C”). Fast adaptation time constantsb were slightly but significantly faster at 37°C when tested across all step displacements (2-way ANOVA). n, number of cells. OR, operating range. Po, fraction of Imet activated at X = 0 nm. X1/2, midpoint of sigmoidal fit to I(X) relation. τfast, τslow, fast and slow adaptation time constants. Percent Aslow, percent of decay attributable to slow adaptation term.