TITLE Slowly recovering Na channel
: Na channel in Large Cell of Corpus Glomerulosum
: Reconstruction of physiological data :Kinetic parameters updated 1 May 2001
NEURON {
SUFFIX Na_cglc
USEION na READ ena WRITE ina
RANGE gnabar, ina
GLOBAL minf, hinf, mtau, htau
}
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
PARAMETER {
gnabar=.120 (mho/cm2) <0,1e9>
}
STATE {
m h
}
ASSIGNED {
v (mV)
celsius (degC) : 6.3
ena (mV)
ina (mA/cm2)
minf hinf
mtau (ms)
htau (ms)
}
INITIAL {
rates(v)
m = minf
h = hinf
}
BREAKPOINT {
SOLVE states METHOD cnexp
ina = gnabar*m*m*m*h*(v - ena)
}
DERIVATIVE states {
rates(v)
m' = (minf - m)/mtau
h' = (hinf - h)/htau
}
FUNCTION alp(v(mV),i) (/ms) { LOCAL a,b,c,q10 :rest = -70 order m,h
q10 = 1 :temp dependence not incorporated
if (i==0) { :m gate
alp = q10*(.03505(/ms)*1(/mV)*(v+42.29529)+1(/ms)*(0.0012285*(1(/mV)*v+42.29529)^2+0.005)^.5)
}else if (i==1){ :h gate
alp = q10*.000187291(/ms)*exp(-v/20.8036(mV))
}
}
FUNCTION bet(v(mV),i)(/ms) { LOCAL a,b,c,q10 :rest = -70 order m,h
q10 = 1
if (i==0) {
bet = q10*.403703(/ms)*(1 - 1/(1 +exp((-1(/mV)*v - 44.6804)/10.0433)))
}else if (i==1){
bet = q10*.424283(/ms)/(1 + exp((-1(/mV)*v - 38.85) / 5.74763 ))
}
}
FUNCTION expM1(x,y) {
if (fabs(x/y) < 1e-6) {
expM1 = y*(1 - x/y/2)
}else{
expM1 = x/(exp(x/y) - 1)
}
}
PROCEDURE rates(v(mV)) {LOCAL a, b
TABLE minf, hinf, mtau, htau DEPEND celsius FROM -100 TO 100 WITH 200
a = alp(v,0) b=bet(v,0)
mtau = 1/(a + b)
minf = a/(a + b)
a = alp(v,1) b=bet(v,1)
htau = 1/(a + b)
hinf = a/(a + b)
}