Figure 3.

The effects of temperature on trains of action potentials in type II taste-bud cells. A: representative trains of action potentials in response to 500-ms +30-pA current injections at different temperatures as indicated. Dotted lines indicate −70 mV and 0 mV, respectively. B: number of overshooting action potentials (AP) during a 500-ms depolarizing current injection at various temperatures as indicated (n = 4–18). C: in the cells that generated a maximum number of action potentials, the interval time (ms) between overshooting peaks of first and second action potentials in the train of action potentials were 284.1 ± 30.2 (n = 3, P < 0.0005) at 10°C; 186.9 ± 41.7 (n = 8, P < 0.0005) at 15°C; 111.9 ± 29.8 (n = 22) at 20°C; 70.2 ± 30.2 (n =17, P < 0.0005) at 25°C; 45.3 ± 15.7 (n = 15, P < 0.0005) at 30°C. D: action potential frequency (Hz), the reciprocal of the interval time in C was 3.6 ± 0.4 (n = 3, P < 0.005) for 10°C; 5.6 ± 1.2 (n = 8, P < 0.005) for 15°C; 9.7 ± 3.2 (n = 22) for 20°C; 17.0 ± 7.3 (n =17, P < 0.0005) for 25°C; and 24.3 ± 7.2 (n = 15, P < 0.0005) for 30°C. P values were obtained from Student’s t test, compared with data at 20°C.