TITLE Potasium Type A current for RD Traub, J Neurophysiol 89:909-921, 2003 COMMENT Implemented by Maciej Lazarewicz 2003 (mlazarew@seas.upenn.edu) ENDCOMMENT INDEPENDENT { t FROM 0 TO 1 WITH 1 (ms) } UNITS { (mV) = (millivolt) (mA) = (milliamp) } NEURON { SUFFIX ka USEION k READ ek WRITE ik RANGE gbar, ik, m, h, alphah, betah, alpham, betam, mtau, htau } PARAMETER { gbar = 0.0 (mho/cm2) v (mV) ek (mV) } ASSIGNED { ik (mA/cm2) minf hinf (1) mtau (ms) htau (ms) alphah (/ms) betah (/ms) alpham (/ms) betam (/ms) } STATE { m h } BREAKPOINT { SOLVE states METHOD cnexp ik = gbar * m * m * m * m * h * ( v - ek ) : debugging: alphah = hinf/htau betah = 1/htau - alphah alpham = minf/mtau betam = 1/mtau - alpham } INITIAL { settables(v) : m = minf m = 0 h = hinf : h = 0.208608 : from F tcr cc run } DERIVATIVE states { settables(v) m' = ( minf - m ) / mtau h' = ( hinf - h ) / htau } UNITSOFF PROCEDURE settables(v (mV)) { TABLE minf, hinf, mtau, htau FROM -120 TO 40 WITH 641 minf = 1 / ( 1 + exp( ( - v - 60 ) / 8.5 ) ) mtau = 0.185 + 0.5 / ( exp( ( v + 35.8 ) / 19.7 ) + exp( ( - v - 79.7 ) / 12.7 ) ) hinf = 1 / ( 1 + exp( ( v + 78 ) / 6 ) ) if( v <= -63 ) { htau = 0.5 / ( exp( ( v + 46 ) / 5 ) + exp( ( - v - 238 ) / 37.5 ) ) }else{ htau = 9.5 } } UNITSON