COMMENT
All the channels are taken from same good old classic articles.
The arrengment was done after:
Kang, S., Kitano, K., and Fukai, T. (2004).
Self-organized two-state membrane potential
transitions in a network of realistically modeled
cortical neurons. Neural Netw 17, 307-312.
Whenever available I used the same parameters they used,
except in n gate:
n' = phi*(ninf-n)/ntau
Kang used phi = 12
I used phi = 1
Written by Albert Gidon & Leora Menhaim (2004).
ENDCOMMENT
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
(S) = (siemens)
}
NEURON {
SUFFIX traub
NONSPECIFIC_CURRENT i
RANGE iL,iNa,iK
RANGE eL, eNa, eK
RANGE gLbar, gNabar, gKbar
RANGE vshift
}
PARAMETER {
gNabar = .03 (S/cm2) :Traub et. al. 1991
gKbar = .015 (S/cm2) :Traub et. al. 1991
gLbar = 0.00014 (S/cm2) :Siu Kang - by email.
eL = -62.0 (mV) :Siu Kang - by email.
eK = -80 (mV) :Siu Kang - by email.
eNa = 90 (mV) :Leora
totG = 0
vshift = 0
}
STATE {
m h n a b
}
ASSIGNED {
v (mV)
i (mA/cm2)
cm (uF)
iL iNa iK(mA/cm2)
gNa gK (S/cm2)
minf hinf ninf
mtau (ms) htau (ms) ntau (ms)
}
BREAKPOINT {
SOLVE states METHOD cnexp
:-------------------------
:Traub et. al. 1991
gNa = gNabar*h*m*m
iNa = gNa*(v - eNa)
gK = gKbar*n : - Traub et. al. 1991
iK = gK*(v - eK)
:-------------------------
iL = gLbar*(v - eL)
i = iL + iK + iNa
:to calculate the input resistance get the sum of
: all the conductance.
totG = gNa + gK + gLbar
}
INITIAL {
rates(v+vshift)
m = minf
h = hinf
n = ninf
}
? states
DERIVATIVE states {
rates(v+vshift)
:Traub Spiking channels
m' = (minf-m)/mtau
h' = (hinf-h)/htau
n' = 2*(ninf-n)/ntau :phi=12 from Kang et. al. 2004
}
? rates
DEFINE Q10 3
PROCEDURE rates(v(mV)) {
:Computes rate and other constants at current v.
:Call once from HOC to initialize inf at resting v.
LOCAL alpha, beta, sum, vt, Q
TABLE mtau,ntau,htau,minf,ninf,hinf
FROM -100 TO 70 WITH 1000
: see Resources/The unreliable Q10.htm for details
: remember that not only Q10 is temprature dependent
: and just astimated here, but also the calculation of
: Q is itself acurate only in about 10% in this range of
: temperatures. the transformation formulation is:
: Q = Q10^(( new(degC) - from_original_experiment(degC) )/ 10)
:--------------------------------------------------------
: This part was taken **directly** from:
: Traub, R. D., Wong, R. K., Miles, R., and Michelson, H. (1991).
: A model of a CA3 hippocampal pyramidal neuron incorporating
: voltage-clamp data on intrinsic conductances.
: J Neurophysiol 66, 635-650.
: Experiments were done in >=32degC for m,h
: Traub et al uses their -60mV as 0mV thus here is the shift
vt = v + 50
Q = Q10^((35 - 32)/ 10)
:"m" sodium activation system
if(vt == 13.1){alpha = 0.32*4}
else{alpha = 0.32*(13.1 - vt)/(exp((13.1 - vt)/4) - 1)}
if(vt == 40.1){beta = 0.28*5}
else{beta = 0.28*(vt - 40.1)/(exp((vt - 40.1)/5)-1)}
sum = alpha + beta
mtau = 1/sum
mtau = mtau/Q
minf = alpha/sum
:"h" sodium inactivation system
alpha = 0.128*exp((17 - vt)/18)
beta = 4/(1 + exp((40 - vt)/5))
sum = alpha + beta
htau = 1/sum
htau = htau/Q
hinf = alpha/sum
:"n" potassium activation system
if(vt == 35.1){ alpha = 0.016*5 }
else{alpha =0.016*(35.1 - vt)/(exp((35.1 - vt)/5) - 1)}
beta = 0.25*exp((20 - vt)/40)
sum = alpha + beta
ntau = 1/sum
ntau = ntau/Q
ninf = alpha/sum
}