TITLE Potasium C type current for RD Traub, J Neurophysiol 89:909-921, 2003 COMMENT Modified with simple speed up *2 factor at bottom - Tom Morse Implemented by Maciej Lazarewicz 2003 (mlazarew@seas.upenn.edu) ENDCOMMENT INDEPENDENT { t FROM 0 TO 1 WITH 1 (ms) } UNITS { (mV) = (millivolt) (mA) = (milliamp) (mM) = (milli/liter) } NEURON { SUFFIX kc_fast USEION k READ ek WRITE ik USEION ca READ cai RANGE gbar, ik } PARAMETER { gbar = 0.0 (mho/cm2) v (mV) ek (mV) cai (mM) } ASSIGNED { ik (mA/cm2) alpha (/ms) beta (/ms) } STATE { m } BREAKPOINT { SOLVE states METHOD cnexp if( 0.004(/mM) * cai < 1 ) { ik = gbar * m * 0.004(/mM) * cai * ( v - ek ) }else{ ik = gbar * m * ( v - ek ) } } INITIAL { settables(v) m = alpha / ( alpha + beta ) m = 0 } DERIVATIVE states { settables(v) m' = alpha * ( 1 - m ) - beta * m } UNITSOFF PROCEDURE settables(v(mV)) { TABLE alpha, beta FROM -120 TO 40 WITH 641 if( v <= -10.0 ) { alpha = 2 / 37.95 * ( exp( ( v + 50 ) / 11 - ( v + 53.5 ) / 27 ) ) : Note that there is typo in the paper - missing minus sign in the front of 'v' beta = 2 * exp( ( - v - 53.5 ) / 27 ) - alpha }else{ alpha = 2 * exp( ( - v - 53.5 ) / 27 ) beta = 0 } : speed-up of C kinetics here. alpha = alpha * 2 beta = beta * 2 } UNITSON