COMMENT Maciej T. Lazarewicz, mlazarew@seas.upenn.edu ENDCOMMENT NEURON { SUFFIX kahp USEION k WRITE ik USEION ca READ cai RANGE gkbar, ik, qinf, tauq } UNITS { (mollar) = (1/liter) (mM) = (millimollar) (mA) = (milliamp) (mV) = (millivolt) (mS) = (millisiemens) } PARAMETER { gkbar = 0.8 (mS/cm2) ek = -75 (mV) } ASSIGNED { v (mV) ik (mA/cm2) cai (mM) qinf (1) tauq (ms) } STATE { q } INITIAL { rates(v) q = qinf } BREAKPOINT { SOLVE states METHOD cnexp ik = (1e-3) * gkbar * q * (v-ek) } DERIVATIVE states { rates(v) q' = (qinf-q)/tauq } PROCEDURE rates(v(mV)) { LOCAL a,b a = 0.01(/ms) * min(cai/500(mM),1) b = 1(/ms)/1000 qinf = a/(a+b) tauq = 1.0/(a+b) } COMMENT Maciej T. Lazarewicz, mlazarew@seas.upenn.edu ENDCOMMENT :------------------------------------------------------------------- FUNCTION fun1(v(mV),V0(mV),A(/ms),B(mV))(/ms) { fun1 = A*exp((v-V0)/B) } FUNCTION fun2(v(mV),V0(mV),A(/ms),B(mV))(/ms) { fun2 = A/(exp((v-V0)/B)+1) } FUNCTION fun3(v(mV),V0(mV),A(/ms),B(mV))(/ms) { if(fabs((v-V0)/B)<1e-6) { :if(v==V0) { fun3 = A*B/1(mV) * (1- 0.5 * (v-V0)/B) } else { fun3 = A/1(mV)*(v-V0)/(exp((v-V0)/B)-1) } } FUNCTION min(x,y) { if (x<=y){ min = x }else{ min = y } }