94 lines
1.3 KiB
Modula-2
94 lines
1.3 KiB
Modula-2
TITLE low threshold potassium channels in VCN auditory neurons
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: k_LT=glt*w^4*z*(v-Ek)
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: based on Rothman and Manis (2003c)
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: Modifications by Yi Zhou for an MSO model
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INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}
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NEURON {
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SUFFIX kLT_VCN2003
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USEION k READ ek WRITE ik
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RANGE gkbar
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RANGE w_inf,z_inf
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RANGE tau_w,tau_z
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RANGE w_exp,z_exp
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RANGE ik,gk
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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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}
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PARAMETER {
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gkbar = 0.04 (mho/cm2)
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ek=-70 (mV)
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celsius =22 (degC)
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dt (ms)
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v (mV)
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}
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STATE {
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w z
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}
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ASSIGNED {
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gk(mho/cm2)
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ik(mA/cm2)
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w_inf
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z_inf
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tau_w
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tau_z
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w_exp
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z_exp
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tadj
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}
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BREAKPOINT {
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SOLVE states
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gk=gkbar *w^4*z
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ik = gk*(v-ek)
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}
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PROCEDURE states() { : this discretized form is more stable
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evaluate_fct(v)
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w = w + w_exp * (w_inf - w)
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z = z + z_exp * (z_inf - z)
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VERBATIM
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return 0;
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ENDVERBATIM
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}
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UNITSOFF
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INITIAL {
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:
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: Q10 was assumed to be 3 for both currents
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:
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tadj = 3.0 ^ ((celsius-22)/ 10 )
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evaluate_fct(v)
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w= w_inf
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z= z_inf
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}
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PROCEDURE evaluate_fct(v(mV)) {LOCAL h
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tau_w = (100/(6*exp((v+60)/6)+16*exp(-(v+60)/45))+1.5)/ tadj
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w_inf = 1/(1+exp(-(v+48)/6))^0.25
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tau_z = (1000/(exp((v+60)/20)+exp(-(v+60)/8))+50)/ tadj
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h=0.5
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z_inf = (1-h)/(1+exp((v+71)/10))+h
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w_exp = 1 - exp(-dt/tau_w)
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z_exp = 1 - exp(-dt/tau_z)
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}
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UNITSON
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