Temperature dependence of the ionic current kinetics of Myxicola giant axons

1. The temperature dependence of the sodium and potassium conductances of Myxicola giant axons was studied in the range of 1-18° C. 2. Analysis of voltage clamp records for step depolarizations of 20-150 mV yielded Q 10 's for ḡ Na , ḡ K , and g 1 of 1·3-1·5. The steady-state parameters m ∞ ( v ), n ∞ ( v ) were independent of temperature. The time constants had Q 10 's of: 2·64 ± 0·2 for τ m ; 2·56 ± 0·2 for τ h ; 3·02 ± 0·3 for τ n . 3. τ h determined from the effects of prepulse duration rather than the decline in sodium current during a step depolarization had a Q 10 of 2·47 ± 0·2.