TITLE Ika CA3
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
NEURON {
SUFFIX kacurrent
NONSPECIFIC_CURRENT ika, ikad
RANGE g, gd, e, ninf, ntau, ndinf, ndtau, linf, ltau
}
PARAMETER {
celsius (degC)
g= 0.048 (mho/cm2)
gd= 0 (mho/cm2)
e= -90 (mV)
}
STATE {
n
nd : distal
l
}
ASSIGNED {
v (mV)
ika (mA/cm2)
ikad (mA/cm2)
ninf
ntau (ms)
ndinf
ndtau (ms)
linf
ltau (ms)
}
PROCEDURE iassign () {
ika=g*n*l*(v-e)
ikad=gd*nd*l*(v-e)
}
BREAKPOINT {
SOLVE states METHOD cnexp
iassign()
}
DERIVATIVE states {
rates(v)
n'= (ninf- n)/ ntau
l'= (linf- l)/ ltau
nd'= (ndinf-nd)/ndtau
}
INITIAL {
rates(v)
n = ninf
l = linf
iassign()
}
PROCEDURE rates(v (mV)) {
LOCAL a, b
UNITSOFF
a = exp(-0.038*(1.5+1/(1+exp(v+40)/5))*(v-11))
b = exp(-0.038*(0.825+1/(1+exp(v+40)/5))*(v-11))
ntau=4*b/(1+a)
if (ntau<0.1) {ntau=0.1}
ninf=1/(1+a)
a=exp(-0.038*(1.8+1/(1+exp(v+40)/5))*(v+1))
b=exp(-0.038*(0.7+1/(1+exp(v+40)/5))*(v+1))
ndtau=2*b/(1+a)
if (ndtau<0.1) {ndtau=0.1}
ndinf=1/(1+a)
a = exp(0.11*(v+56))
ltau=0.26*(v+50)
if (ltau<2) {ltau=2}
linf=1/(1+a)
UNITSON
}