TITLE HH KM channel
: Hodgkin - Huxley KM channel with parameters from
: US Bhalla and JM Bower, J. Neurophysiol. 69:1948-1983 (1993)
: Andrew Davison, The Babraham Institute, 1998.
NEURON {
SUFFIX kM
USEION k READ ek WRITE ik
RANGE gkbar, ik
GLOBAL xinf, xtau
}
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}
PARAMETER {
v (mV)
dt (ms)
gkbar=.036 (mho/cm2) <0,1e9>
ek = -70 (mV)
}
STATE {
x
}
ASSIGNED {
ik (mA/cm2)
xinf
xtau (ms)
}
INITIAL {
rates(v)
x = xinf
}
BREAKPOINT {
SOLVE states METHOD cnexp
ik = gkbar*x*(v - ek)
}
DERIVATIVE states {
rates(v)
x' = (xinf - x)/xtau
}
PROCEDURE rates(v(mV)) {
TABLE xinf, xtau FROM -100 TO 100 WITH 200
xinf = 1/(1 + exp(-(v*1(/mV) + 35)/5))
xtau = 1000(ms)/(3.3*exp((v*1(/mV) + 35)/40) + exp(-(v*1(/mV) + 35)/20))
}