TITLE K-fast channel from Korngreen and Sakmann 2000 : M.Migliore June 2001 NEURON { SUFFIX iA USEION k READ ek WRITE ik RANGE gbar,ik,ninf,linf,taul,taun GLOBAL tq,qq, q10,vmin, vmax,tadj,temp } UNITS { (mA) = (milliamp) (mV) = (millivolt) (pS) = (picosiemens) (um) = (micron) } PARAMETER { v (mV) celsius (degC) Tscale = 10 (degC) gbar=0.0 (pS/um2) offn=-47 (mV) offl=-66 (mV) slon=29 (mV) slol=10 (mV) qq=5 tq=-55 ek (mV) vmin = -120 (mV) vmax = 100 (mV) temp = 21 (degC) : original temp q10 = 2.3 offmt = -71 (mV) slomt = 59 (mV) taummin = 0.34 (ms) taumdiff = 0.92 (ms) offht = -73 (mV) sloht = 23 (mV) tauhmin = 8 (ms) tauhdiff = 49 (ms) } STATE { n l } ASSIGNED { ik (mA/cm2) ninf linf taul (ms) taun (ms) tadj } INITIAL { rates(v) n=ninf l=linf } BREAKPOINT { SOLVE states METHOD cnexp ik = (1e-4)*gbar*n^4*l*(v-ek) } DERIVATIVE states { : exact when v held constant; integrates over dt step rates(v) n' = (ninf - n)/taun l' = (linf - l)/taul } PROCEDURE rates(v (mV)) { :callable from hoc tadj= q10^((celsius-temp)/Tscale) ninf = 1/(1 + exp(-(v-offn)/slon)) linf = 1/(1 + exp((v-offl)/slol)) taun = (taummin+taumdiff*exp(-((offmt-v)/slomt)^2))/tadj taul = (tauhmin+tauhdiff*exp(-((offht-v)/sloht)^2))/tadj }