:Comment : mtau deduced from text (said to be 6 times faster than for NaTa)
:Comment : so I used the equations from NaT and multiplied by 6
:Reference : Modeled according to kinetics derived from Magistretti & Alonso 1999
:Comment: corrected rates using q10 = 2.3, target temperature 34, orginal 21
NEURON {
SUFFIX Nap_Et2
USEION na READ ena WRITE ina
RANGE gNap_Et2bar, gNap_Et2, ina
}
UNITS {
(S) = (siemens)
(mV) = (millivolt)
(mA) = (milliamp)
}
PARAMETER {
gNap_Et2bar = 0.00001 (S/cm2)
}
ASSIGNED {
v (mV)
ena (mV)
ina (mA/cm2)
gNap_Et2 (S/cm2)
mInf
mTau
mAlpha
mBeta
hInf
hTau
hAlpha
hBeta
}
STATE {
m
h
}
BREAKPOINT {
SOLVE states METHOD cnexp
gNap_Et2 = gNap_Et2bar*m*m*m*h
ina = gNap_Et2*(v-ena)
}
DERIVATIVE states {
rates()
m' = (mInf-m)/mTau
h' = (hInf-h)/hTau
}
INITIAL{
rates()
m = mInf
h = hInf
}
PROCEDURE rates(){
LOCAL qt
qt = 2.3^((34-21)/10)
UNITSOFF
mInf = 1.0/(1+exp((v- -52.6)/-4.6))
if(v == -38){
v = v+0.0001
}
mAlpha = (0.182 * (v- -38))/(1-(exp(-(v- -38)/6)))
mBeta = (0.124 * (-v -38))/(1-(exp(-(-v -38)/6)))
mTau = 6*(1/(mAlpha + mBeta))/qt
if(v == -17){
v = v + 0.0001
}
if(v == -64.4){
v = v+0.0001
}
hInf = 1.0/(1+exp((v- -48.8)/10))
hAlpha = -2.88e-6 * (v + 17) / (1 - exp((v + 17)/4.63))
hBeta = 6.94e-6 * (v + 64.4) / (1 - exp(-(v + 64.4)/2.63))
hTau = (1/(hAlpha + hBeta))/qt
UNITSON
} |