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102 lines
2.2 KiB
102 lines
2.2 KiB
2 years ago
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TITLE h current for Octopus cells of Cochlear Nucleus
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: From Bal and Oertel (2000)
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: M.Migliore Oct. 2001
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: Modified, P. Manis July 2014.
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NEURON {
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THREADSAFE
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SUFFIX hcno
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NONSPECIFIC_CURRENT i
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RANGE gbar, eh, gh
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GLOBAL hinf, tau1, tau2
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}
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UNITS {
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(mA) = (milliamp)
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(mV) = (millivolt)
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(pS) = (picosiemens)
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(um) = (micron)
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R = (k-mole)(joule/degC)
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F = (faraday)(kilocoulombs)
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}
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PARAMETER {
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gbar = 0.0005 (mho/cm2)
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vhalf1 = -50 (mV) : v 1/2 for forward
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vhalf2 = -84 (mV) : v 1/2 for backward
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gm1 = 0.3 :(mV) : slope for forward
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gm2 = 0.6 : (mV) : slope for backward
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zeta1 = 3 : (/ms)
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zeta2 = 3 : (/ms)
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a01 = 0.008 (/ms)
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a02 = 0.0029 (/ms)
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frac = 0.0
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c0 = 273.16 (degC)
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thinf = -66 (mV) : inact inf slope
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qinf = 7 (mV) : inact inf slope
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q10tau = 4.5 : from Magee (1998)
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v (mV)
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q10g = 2.0 : Rothman...
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}
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ASSIGNED {
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celsius (degC)
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i (mA/cm2)
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gh (mho/cm2)
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eh (mV) : must be explicitly def. in hoc
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hinf
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tau1 (ms)
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tau2 (ms)
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qg () : computed q10 for gnabar based on q10g
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q10 ()
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ssih
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}
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STATE { h1 h2 }
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BREAKPOINT {
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SOLVE states METHOD derivimplicit
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gh = qg*gbar*(h1*frac + h2*(1.0-frac))
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i = gh * (v - eh)
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}
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INITIAL {
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qg = q10g^((celsius-33.0)/10.0 (degC)) :note original measurements made at 33 C
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q10 = q10tau^((celsius - 22.0)/10.0 (degC)) : if you don't like room temp, it can be changed!
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rates(v)
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h1=hinf
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h2=hinf
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ssih = 0.
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}
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DERIVATIVE states {
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rates(v)
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h1' = (hinf - h1)/tau1
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h2' = (hinf - h2)/tau2
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}
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PROCEDURE rates(v (mV)) {
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tau1 = bet1(v)/(q10*a01*(1.0+alp1(v)))
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tau2 = bet2(v)/(q10*a02*(1.0+alp2(v)))
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hinf = 1.0/(1.0+exp((v-thinf)/qinf))
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}
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FUNCTION alp1(v(mV)) {
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alp1 = exp(1e-3*zeta1*(v-vhalf1)*F/(R*(c0+celsius)))
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}
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FUNCTION bet1(v(mV)) {
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bet1 = exp(1.e-3*zeta1*gm1*(v-vhalf1)*F/(R*(c0+celsius)))
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}
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FUNCTION alp2(v(mV)) {
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alp2 = exp(1.e-3*zeta2*(v-vhalf2)*F/(R*(c0+celsius)))
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}
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FUNCTION bet2(v(mV)) {
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bet2 = exp(1.e-3*zeta2*gm2*(v-vhalf2)*F/(R*(c0+celsius)))
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}
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