:Comment : The persistent component of the K current
:Reference : : Voltage-gated K+ channels in layer 5 neocortical pyramidal neurones from young rats:subtypes and gradients,Korngreen and Sakmann, J. Physiology, 2000
:Comment : shifted -10 mv to correct for junction potential
:Comment: corrected rates using q10 = 2.3, target temperature 34, orginal 21
NEURON {
SUFFIX K_Pst
USEION k READ ek WRITE ik
RANGE gK_Pstbar, gK_Pst, ik, offm, slom, offmt, slomt, taummin, taumdiff1, taumdiff2, offh, sloh, offht1, offht2, sloht, tauhmean, tauhdiff1, tauhdiff2
}
UNITS {
(S) = (siemens)
(mV) = (millivolt)
(mA) = (milliamp)
}
PARAMETER {
gK_Pstbar = 0.00001 (S/cm2)
offm = -11 (mV)
slom = 12 (mV)
offmt = -10 (mV)
slomt = 38.46153846 (mV)
taummin = 1.25 (ms)
taumdiff1 = 175.03 (ms)
taumdiff2 = 13 (ms)
offh = -64 (mV)
sloh = 11 (mV)
offht1 = -65 (mV)
offht2 = -85 (mV)
sloht = 48 (mV)
tauhmean = 360 (ms)
tauhdiff1 = 1010 (ms)
tauhdiff2 = 24 (ms/mV)
}
ASSIGNED {
v (mV)
ek (mV)
ik (mA/cm2)
gK_Pst (S/cm2)
mInf
mTau
hInf
hTau
}
STATE {
m
h
}
BREAKPOINT {
SOLVE states METHOD cnexp
gK_Pst = gK_Pstbar*m*m*h
ik = gK_Pst*(v-ek)
}
DERIVATIVE states {
rates()
m' = (mInf-m)/mTau
h' = (hInf-h)/hTau
}
INITIAL{
rates()
m = mInf
h = hInf
}
PROCEDURE rates(){
LOCAL qt, thresh
qt = 2.3^((34-21)/10)
thresh = offmt-slomt/2*log(taumdiff1/taumdiff2)
UNITSOFF
mInf = (1/(1 + exp((offm-v)/slom)))
if(v<thresh){
mTau = (taummin+taumdiff1*exp(-(offmt-v)/slomt))/qt
} else {
mTau = ((taummin+taumdiff2*exp((offmt-v)/slomt)))/qt
}
hInf = 1/(1 + exp(-(offh-v)/sloh))
hTau = (tauhmean+(tauhdiff1-tauhdiff2*(offht1-v))*exp(-((offht2-v)/sloht)^2))/qt
UNITSON
}