: Slowly inactivating K+ channel
NEURON {
SUFFIX IKsin
USEION k READ ki, ko WRITE ik
RANGE gKsbar, ik, gk
}
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
(mM) = (milli/liter)
}
INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}
PARAMETER {
v (mV)
dt (ms)
gKsbar= 0.00014 (mho/cm2) <0,1e9>
}
STATE {
a b
}
ASSIGNED {
ik (mA/cm2)
ainf binf
atau (ms)
btau (ms)
gk (mho/cm2)
ek (mV)
ki (mM)
ko (mM)
}
INITIAL {
rate(v)
a = ainf
b = binf
}
BREAKPOINT {
SOLVE states METHOD cnexp
gk = gKsbar * a * b
ek = 25 * log(ko/ki)
ik = gk*(v-ek)
}
DERIVATIVE states {
rate(v)
a' = (ainf-a)/atau
b' = (binf-b)/btau
}
UNITSOFF
PROCEDURE rate(v (mV)) {LOCAL va, vb, vc, vd
va = v + 34
vb = v + 65
vd = v + 63.6
if (fabs(va)<1e-04){ va = va+0.00001 }
ainf = 1/(1 + exp(-va/6.5))
atau = 10
:atau=6
if (fabs(vb)<1e-04){ vb = vb+0.00001 }
binf = 1/(1 + exp(vb/6.6))
if (fabs(vd)<1e-04){ vd = vd+0.00001 }
btau = 200 + 3200 / (1 + exp(-vd/4))
:btau = 200 + 3200 / (1 + exp(-vd/4))
}
UNITSON