Figure 5

Different temperature ranges of impulse generation between TTXs/TRPM8 and TTXr/TRPM8 DRG neurons. A-B) Representative traces of action potential firing following a cooling temperature ramp in TTXs/TRPM8 neuron (A) and TTXr/TRPM8 neuron (B). Left insets in both (A) and (B) show threshold temperatures and initial action potentials (at expanded scale). Right insets show temperatures at which action potentials failed (A) or at which last one was recorded (B). The bottom traces show cooling temperature ramp from 29°C to 19°C for the TTXs cell (A) and from 29°C to 10°C for the TTXr cell. C) Summary data showing the threshold temperatures at which TTXs/TRPM8 (n = 9) and TTXr/TRPM8 cells (n = 7) started to fire action potentials and the temperatures at which action potentials failed or cooling was ended. (D) Summary data showing the threshold temperatures at which TTXs/TRPM8 (n = 9) and TTXr/TRPM8 cells (n = 7) started to depolarize in response to the cooling temperature ramp. Data represent mean ± SEM, *P < 0.05.