Cold-sensitive neurons | Temperature threshold (°C) | Resting potential (mV) | Input resistance (mΩ) | Rheobase current (pA) | AP duration (ms) | Inward rectification index (%) | Firing frequency at 2 rheobase (Hz) | Phenotype incidence (%) | |
---|---|---|---|---|---|---|---|---|---|
Control (n = 36) | Cold thermoreceptor-like (n = 34) | 27.8 ± 0.6 | −46.0 ± 1.3 | 536 ± 42 | 67 ± 7 | 1.01 ± 0.04 | 51.4 ± 1.7 | 58.9 ± 4.5 | 94.4 |
Nociceptor-like (n = 2) | 23.6 ± 1.6 | −45.0 ± 0.0 | 392 ± 90 | 68 ± 3 | 1.55 ± 0.15 | 57.9 ± 0.7 | 27.0 ± 5.0 | 5.6 | |
Injured (n = 37) | Cold thermoreceptor-like (n = 26) | 27.5 ± 0.7 | −45.8 ± 2.0 | 394 ± 34 | 58 ± 5 | 0.91 ± 0.04 | 55.0 ± 2.0 | 67.8 ± 7.0 | 70.3 |
Nociceptor-like (n = 11) | 26.5 ± 0.9 | −44.3 ± 2.1 | 494 ± 62 | 75 ± 7 | 1.75 ± 0.20*** | 53.1 ± 3.4 | 28.9 ± 5.9** | 29.7* |
↵aTemperature thresholds were determined in intact neurons by calcium imaging. AP, Action potential. Input resistance was measured from the slope of peak voltage response to a series of negative current steps. AP duration was measured at half-amplitude. Inward rectification index was measured as 100 × (Vpeak − Vsteady-state)/Vpeak, during hyperpolarizing voltage responses that reached a voltage peak value ∼−120 mV. The number of spikes at 2 × rheobase current were counted in a 500 ms period.
↵*p = 0.013 (F test).
↵**p = 0.002;
↵***p < 0.001; unpaired t test.