: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, offm, slom, offma, offmb, sloma, slomb, tauma, taumb, taummax, offh, sloh, offha, offhb, sloha, slohb, tauha, tauhb, tauhmax
}
UNITS {
(S) = (siemens)
(mV) = (millivolt)
(mA) = (milliamp)
}
PARAMETER {
gNap_Et2bar = 0.00001 (S/cm2)
offm = -52.6 (mV)
slom = 4.6 (mV)
offma = -38 (mV)
offmb = -38 (mV)
sloma = 6.0 (mV)
slomb = 6.0 (mV)
tauma = 5.49451
taumb = 8.06452
taummax = 6.0 (ms)
offh = -48.8 (mV)
sloh = 10.0 (mV)
offha = -17 (mV)
offhb = -64.4 (mV)
sloha = 4.63 (mV)
slohb = 2.63 (mV)
tauha = 347222.2
tauhb = 144092.2
tauhmax = 1.0 (ms)
}
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((offm-v)/slom))
if(v == offma){
v = v+0.0001
}
if(v == offmb){
v = v+0.0001
}
mAlpha = -(offma-v)/(1-(exp((offma-v)/sloma)))/tauma
mBeta = (offmb-v)/(1-(exp(-(offmb-v)/slomb)))/taumb
mTau = taummax*(1/(mAlpha + mBeta))/qt
if(v == offha){
v = v + 0.0001
}
if(v == offhb){
v = v+0.0001
}
hInf = 1.0/(1+exp(-(offh-v)/sloh))
hAlpha = (offha-v) / (1 - exp(-(offha-v)/sloha))/tauha
hBeta = -(offhb-v) / (1 - exp((offhb-v)/slohb))/tauhb
hTau = tauhmax*(1/(hAlpha + hBeta))/qt
UNITSON
}