TITLE K-DR channel : from Klee Ficker and Heinemann : modified to account for Dax et al. : M.Migliore 1997 : thread-safe 2010-05-31 Ben Suter : 2010-11-07 Ben Suter, removing "kdr" from parameter names, reformatting, setting sh = 0 (was 24 mV) : : ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: : Copyright 2011, Benjamin Suter (for changes only) : ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: UNITS { (mA) = (milliamp) (mV) = (millivolt) } PARAMETER { v (mV) celsius (degC) ek (mV) : must be explicitely def. in hoc gbar = 0.003 (mho/cm2) vhalfn = 13 (mV) a0n = 0.02 (/ms) zetan = -3 (1) gmn = 0.7 (1) nmax = 2 (1) q10 = 1 sh = 0 } NEURON { THREADSAFE SUFFIX kdr USEION k READ ek WRITE ik RANGE g, gbar, sh, ninf,taun } STATE { n } ASSIGNED { ik (mA/cm2) ninf g taun } BREAKPOINT { SOLVE states METHOD cnexp g = gbar*n ik = g*(v-ek) } INITIAL { rates(v) n=ninf } FUNCTION alpn(v(mV)) { alpn = exp(1.e-3*zetan*(v-vhalfn-sh)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION betn(v(mV)) { betn = exp(1.e-3*zetan*gmn*(v-vhalfn-sh)*9.648e4/(8.315*(273.16+celsius))) } DERIVATIVE states { : exact when v held constant; integrates over dt step rates(v) n' = (ninf - n)/taun } PROCEDURE rates(v (mV)) { :callable from hoc LOCAL a,qt qt = q10^((celsius-24)/10) a = alpn(v) ninf = 1/(1+a) taun = betn(v)/(qt*a0n*(1+a)) if (taun