TITLE Cerebellum Granule Cell Model COMMENT Kir channel Author: E.D'Angelo, T.Nieus, A. Fontana Last revised: 8.10.2000 Old values: gkbar = 0.0003 (mho/cm2) ENDCOMMENT NEURON { SUFFIX GRC_KIR USEION k READ ek WRITE ik RANGE gkbar, ik, g, alpha_d, beta_d RANGE Aalpha_d, Kalpha_d, V0alpha_d RANGE Abeta_d, Kbeta_d, V0beta_d RANGE d_inf, tau_d } UNITS { (mA) = (milliamp) (mV) = (millivolt) } PARAMETER { Aalpha_d = 0.13289 (/ms) :Kalpha_d = -0.041 (/mV) Kalpha_d = -24.3902 (mV) V0alpha_d = -83.94 (mV) Abeta_d = 0.16994 (/ms) :Kbeta_d = 0.028 (/mV) Kbeta_d = 35.714 (mV) V0beta_d = -83.94 (mV) v (mV) gkbar = 0.0009 (mho/cm2) ek = -84.69 (mV) celsius = 30 (degC) } STATE { d } ASSIGNED { ik (mA/cm2) d_inf tau_d (ms) g (mho/cm2) alpha_d (/ms) beta_d (/ms) } INITIAL { rate(v) d = d_inf } BREAKPOINT { SOLVE states METHOD derivimplicit g = gkbar*d : primo ordine!!! ik = g*(v - ek) alpha_d = alp_d(v) beta_d = bet_d(v) } DERIVATIVE states { rate(v) d' =(d_inf - d)/tau_d } FUNCTION alp_d(v(mV))(/ms) { LOCAL Q10 Q10 = 3^((celsius-20(degC))/10(degC)) alp_d = Q10*Aalpha_d*exp((v-V0alpha_d)/Kalpha_d) } FUNCTION bet_d(v(mV))(/ms) { LOCAL Q10 Q10 = 3^((celsius-20(degC))/10(degC)) bet_d = Q10*Abeta_d*exp((v-V0beta_d)/Kbeta_d) } PROCEDURE rate(v (mV)) {LOCAL a_d, b_d TABLE d_inf, tau_d DEPEND Aalpha_d, Kalpha_d, V0alpha_d, Abeta_d, Kbeta_d, V0beta_d, celsius FROM -100 TO 30 WITH 13000 a_d = alp_d(v) b_d = bet_d(v) tau_d = 1/(a_d + b_d) d_inf = a_d/(a_d + b_d) }