TITLE A fast A-type Potassium current COMMENT Used in Role of a Striatal Slowly Inactivating Potassion Current in Short-term Facilitation of Corticostriatal Inputs" A computer Simulation Study" (Mahon et al. 2000) Implemented by Kevin M. Biddell kevin.biddell@gmail.com 7/13/06 NOTE: 1S=1mho Neuron wants the units in mhos not millisiemens, please note the conversion! ENDCOMMENT UNITS { (mA) = (milliamp) (mV) = (millivolt) } NEURON { SUFFIX KAfm USEION k WRITE ik RANGE gkafmbar, gkafm } INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} PARAMETER { ek = -73 (mV) gkafmbar= 0.00009 (mho/cm2) :0.09 mS Etemp = 22 :delord correspondence 11/15/06 Vsm = -33.1 ksm = 7.5 tom = 1 Vsh = -70.4 ksh = -7.6 toh = 25 } STATE { m h } ASSIGNED { ik (mA/cm2) v (mV) celsius (degC) minf hinf mtau htau gkafm } BREAKPOINT { SOLVE states METHOD cnexp gkafm = gkafmbar*m*h ik = gkafm*(v - ek) } UNITSOFF INITIAL { rates(v) m= minf h= hinf } DERIVATIVE states { :Computes states variable m at the current v and dt. rates(v) m' = ( minf - m ) / mtau h' = (hinf - h ) / htau } PROCEDURE rates(v) { :Computes rate and other constants at current v. Call once from HOC to initialize inf at resting v. LOCAL q10,tadj q10 = 2.5 tadj=q10^((celsius-Etemp)/10) minf=1/(1+exp(-(v-Vsm)/ksm)) hinf=1/(1+exp(-(v-Vsh)/ksh)) mtau=tom/tadj htau=toh/tadj } UNITSON