Table 1.

Voltage-dependent conductance parameters

Conductance state variablesnGmax(S/cm2)Vrev (mV)α (sec−1)β (sec−1)
gNa-f
 Activation30.01387.390.9(V + 19)/(1 − exp(−(V + 19)/10))36 exp(−0.055(V + 44))
 Inactivation10.315 exp(−0.3(V + 44))4.5/(1 + exp(−(V + 11)/5))
gNa-r
 Activation15e−487.390.00024 − 0.015(V − 4.5)/((exp(−(V − 4.5)/6.8) − 1))0.14 + 0.047(V + 44)/(exp((V + 44)/0.11) − 1))
 Inactivation10.96*exp(−(V + 80)/62.5)0.03*exp((V + 83.3)/16.1)
gNa-p
 Activation12e−487.390.091(V + 42)/(1 − exp(−(V + 42)/5))−0.062(V + 42)/(1 − exp((V + 42)/5))
x = 1/(1 + exp(−(V + 42)/5))
τ = 5/(α + β)
gK-V
 Activation40.003−84.690.13(V + 25)/(1 − exp(−(V + 25)/10))1.69 exp(−0.0125(V + 35))
gK-A
 Activation30.004−84.6914.67/(1 + exp(−(V + 9.17)/23.32))2.98(exp(−(V + 18.28)/19.47))
 Inactivation10.33/(1 + exp((V + 111.33)/12.84))0.31/(1 + exp(−(V + 49.95)/8.9))
x = 1/(1 + exp(−(V + 46.7)/19.8))
y = 1/(1 + exp((V + 78.8)/8.4))
gK-IR
 Activation19e−4−84.690.4 exp(−0.041(V + 83.94))0.51 exp(0.028(V + 83.94))
gK-Ca
 Activation10.004−84.692.5/(1 + 1.5e − 3/[Ca] exp(−0.085V))1.5/(1 + [Ca]/(0.15e − 3 exp(−0.085V)))
gCa
 Activation24.6e−4129.330.15 exp(0.063 (V + 29.06))0.089 exp(−0.039(V + 18.66))
 Inactivation1*0.0039 exp(−0.055(V + 48))0.0039 exp(0.012(V + 48))
gK-slow
 Activation13.5e−4−84.690.008 exp(0.025(V + 30))0.008 exp(−0.05(V + 30))
x = 1/(1 + exp(−(V + 30)/6))
  • This Table reports the equations used to calculate αx, βx, αy, and βy (see Eqs. 3 and 4) for the membrane conductances used in the model (in a few cases x andy are reported; see Eq. 9). The number of gating particles (n), maximum conductance (Gmax), and ionic reversal potential (* resting value for Ca2+) used to calculate ionic currents are also shown.