NEURON {
SUFFIX kd
USEION k READ ek WRITE ik
RANGE g, G
RANGE minf, taum, i
RANGE tbase, tamp, vhalf, k
}
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
PARAMETER {
g = 0.012 (siemens/cm2) <0,1e9>
}
ASSIGNED {
v (mV)
ek (mV)
ik (mA/cm2)
G (siemens/cm2)
minf
taum (ms)
i
}
STATE {
m
}
BREAKPOINT {
SOLVE states METHOD cnexp
G = g*m*m*m*m
i = G*(v-ek)
ik=i
}
INITIAL {
rate(v)
m = minf
}
DERIVATIVE states {
rate(v)
m' = (minf-m)/taum
}
PROCEDURE rate(v (mV)) {
UNITSOFF
minf = minffun(v)
taum = taumfun(v)
UNITSON
}
FUNCTION minffun(v(mV)) {
TABLE FROM -150 TO 150 WITH 500
minffun = 1/(1+exp((v+13.3)/-9.8))
}
FUNCTION taumfun(v(mV)) {
TABLE FROM -150 TO 150 WITH 500
taumfun = 104.4 - 12.8/(1+exp((v+28.3)/-19.2)) :taumfun = 14.4 - 12.8/(1+exp((v+28.3)/-19.2))
}