TITLE HH channel : Mel-modified Hodgkin - Huxley conductances (after Ojvind et al.) VERBATIM static const char rcsid[]="\$Id: hh3.mod,v 1.1 1996/05/19 19:26:28 karchie Exp \$"; ENDVERBATIM NEURON { SUFFIX hh3 USEION na READ ena WRITE ina USEION k READ ek WRITE ik NONSPECIFIC_CURRENT il RANGE gnabar, gkbar, gl, el GLOBAL taus,taun,taum,tauh,tausb GLOBAL tausv,tausd,mN,nN } UNITS { (mA) = (milliamp) (mV) = (millivolt) } INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} PARAMETER { v (mV) celsius = 37 (degC) dt (ms) gnabar=.20 (mho/cm2) gkbar=.12 (mho/cm2) gl=.0001 (mho/cm2) ena = 40 (mV) ek = -80 (mV) el = -70.0 (mV) : steady state at v = -65 mV taum=0.05 tauh=0.5 taus=50 tausv=30 tausd=1 taun=1 mN=3 nN=3 tausb=0.5 } STATE { m h n s } ASSIGNED { ina (mA/cm2) ik (mA/cm2) il (mA/cm2) } BREAKPOINT { SOLVE states ina = gnabar*h*s*(v - ena)*m^mN ik = gkbar*(v - ek)*n^nN :ina = gnabar*m*m*h*(v - ena) :ik = gkbar*n*n*(v - ek) il = gl*(v - el) } PROCEDURE states() { : exact when v held constant LOCAL sigmas sigmas=1/(1+exp((v+tausv)/tausd)) m = m + (1 - exp(-dt/taum))*(1 / (1 + exp((v + 40)/(-3))) - m) h = h + (1 - exp(-dt/tauh))*(1 / (1 + exp((v + 45)/3)) - h) s = s + (1 - exp(-dt/(taus*sigmas+tausb)))*(1 / (1 + exp((v + 44)/3)) - s) n = n + (1 - exp(-dt/taun))*(1 / (1 + exp((v + 40)/(-3))) - n) VERBATIM return 0; ENDVERBATIM }