TITLE K-A channel from Klee Ficker and Heinemann : modified to account for Dax A Current ---------- : M.Migliore Jun 1997 UNITS { (mA) = (milliamp) (mV) = (millivolt) } PARAMETER { v (mV) gkabar=.008 (mho/cm2) vhalfn=-1 (mV) vhalfl=-56 (mV) a0l=0.05 (/ms) a0n=.1 (/ms) zetan=-1.8 (1) zetal=3 (1) gmn=0.39 (1) gml=1 (1) lmin=2 (mS) nmin=0.1 (mS) pw=-1 (1) tq=-40 qq=5 q10=5 qtl=1 ek } NEURON { SUFFIX kad USEION k READ ek WRITE ik RANGE gkabar,gka GLOBAL ninf,linf,taul,taun,lmin } STATE { n l } ASSIGNED { ik (mA/cm2) ninf linf taul taun gka } BREAKPOINT { SOLVE states METHOD cnexp gka = gkabar*n*l ik = gka*(v-ek) } INITIAL { rates(v) n=ninf l=linf } FUNCTION alpn(v(mV)) { LOCAL zeta zeta=zetan+pw/(1+exp((v-tq)/qq)) alpn = exp(1.e-3*zeta*(v-vhalfn)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION betn(v(mV)) { LOCAL zeta zeta=zetan+pw/(1+exp((v-tq)/qq)) betn = exp(1.e-3*zeta*gmn*(v-vhalfn)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION alpl(v(mV)) { alpl = exp(1.e-3*zetal*(v-vhalfl)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION betl(v(mV)) { betl = exp(1.e-3*zetal*gml*(v-vhalfl)*9.648e4/(8.315*(273.16+celsius))) } DERIVATIVE states { rates(v) n' = (ninf - n)/taun l' = (linf - l)/taul } 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