TITLE gh channel channel : Hodgkin - Huxley h channel NEURON { SUFFIX gh USEION k READ ek WRITE ik USEION na READ ena WRITE ina RANGE ghbar, ik, ina,htau, half, slp,inf } UNITS { (mA) = (milliamp) (mV) = (millivolt) } PARAMETER { v (mV) ghbar =.001 (mho/cm2) <0,1e9> htau = 50 (ms) half=-80 (mV) slp=8 (mV) ek = -77 (mV) ena = 50 (mV) } STATE { n } ASSIGNED { ik (mA/cm2) ina (mA/cm2) inf } INITIAL { rate(v) n = inf } BREAKPOINT { SOLVE states METHOD derivimplicit ik = 0.7*ghbar*n*(v - ek) ina = 0.3*ghbar*n*(v - ena) } DERIVATIVE states { rate(v) n' = (inf - n)/htau } UNITSOFF PROCEDURE rate(v(mV)) { TABLE inf DEPEND half,slp FROM -100 TO 100 WITH 200 inf = 1/(1+exp((v-half)/slp)) } UNITSON