UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
NEURON {
SUFFIX IM
USEION k READ ek WRITE ik
RANGE gbar,ik, vhalf1, vhalf2, k1, k2, c1, c2
GLOBAL minf, mtau
}
INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}
PARAMETER {
v (mV)
dt (ms)
gbar = 0.001 (mho/cm2)
ek
mmin = 7 (ms)
vhalf1 = -63
vhalf2 = -63
k1 = 15
k2 = 15
c1 = 0.003
c2 = 0.003
}
STATE {
m
}
ASSIGNED {
ik
minf
mtau (ms)
}
BREAKPOINT {
SOLVE state METHOD cnexp
ik = gbar*m*(v - ek)
}
INITIAL {
rates(v)
m = minf
}
DERIVATIVE state { :Computes state variable h at current v and dt.
rates(v)
m' = (minf - m)/mtau
}
PROCEDURE rates(v(mV)) { :Computes rate and other constants at current v.
:Call once from HOC to initialize inf at resting v.
: TABLE rinf, rexp, tau_r DEPEND dt, p FROM -200 TO 100 WITH 300
LOCAL a, b
minf = 1/(1 + exp(-(v+27(mV))/7(mV)))
a = c1/exp(-(v-vhalf1)/k1)
b = c2/exp((v-vhalf2)/k2)
mtau = 1/(a+b)
if (mtau<mmin) {mtau = mmin}
}
UNITSON