TITLE Cerebellum Granule Cell Model
COMMENT
KM channel
Author: A. Fontana
CoAuthor: T.Nieus Last revised: 20.11.99
ENDCOMMENT
NEURON {
SUFFIX GRC_KM
USEION k READ ek WRITE ik
RANGE gkbar, ik, g, alpha_n, beta_n
RANGE Aalpha_n, Kalpha_n, V0alpha_n
RANGE Abeta_n, Kbeta_n, V0beta_n
RANGE V0_ninf, B_ninf
RANGE n_inf, tau_n
}
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
PARAMETER {
Aalpha_n = 0.0033 (/ms)
Kalpha_n = 40 (mV)
V0alpha_n = -30 (mV)
Abeta_n = 0.0033 (/ms)
Kbeta_n = -20 (mV)
V0beta_n = -30 (mV)
V0_ninf = -35 (mV) :-30
B_ninf = 6 (mV) :6:4 rimesso a 6 dopo calibrazione febbraio 2003
v (mV)
gkbar= 0.00025 (mho/cm2) :0.0001
ek = -84.69 (mV)
celsius = 30 (degC)
}
STATE {
n
}
ASSIGNED {
ik (mA/cm2)
n_inf
tau_n (ms)
g (mho/cm2)
alpha_n (/ms)
beta_n (/ms)
}
INITIAL {
rate(v)
n = n_inf
}
BREAKPOINT {
SOLVE states METHOD derivimplicit
g = gkbar*n
ik = g*(v - ek)
alpha_n = alp_n(v)
beta_n = bet_n(v)
}
DERIVATIVE states {
rate(v)
n' =(n_inf - n)/tau_n
}
FUNCTION alp_n(v(mV))(/ms) { LOCAL Q10
Q10 = 3^((celsius-22(degC))/10(degC))
alp_n = Q10*Aalpha_n*exp((v-V0alpha_n)/Kalpha_n)
}
FUNCTION bet_n(v(mV))(/ms) { LOCAL Q10
Q10 = 3^((celsius-22(degC))/10(degC))
bet_n = Q10*Abeta_n*exp((v-V0beta_n)/Kbeta_n)
}
PROCEDURE rate(v (mV)) {LOCAL a_n, b_n
TABLE n_inf, tau_n
DEPEND Aalpha_n, Kalpha_n, V0alpha_n,
Abeta_n, Kbeta_n, V0beta_n, V0_ninf, B_ninf, celsius FROM -100 TO 30 WITH 13000
a_n = alp_n(v)
b_n = bet_n(v)
tau_n = 1/(a_n + b_n)
: n_inf = a_n/(a_n + b_n)
n_inf = 1/(1+exp(-(v-V0_ninf)/B_ninf))
}